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The set command can be used to sets _lots_ of options. No screen is drawn, however, until a plot, splot, or replot command is given.

The show command shows their settings; show all shows all the settings.

If a variable contains time/date data, show will display it according to the format currently defined by set timefmt, even if that was not in effect when the variable was initially defined.

set angles

By default, gnuplot assumes the independent variable in polar graphs is in units of radians. If set angles degrees is specified before set polar, then the default range is [0:360] and the independent variable has units of degrees. This is particularly useful for plots of data files. The angle setting also applies to 3-d mapping as set via the set mapping command.


     set angles {degrees | radians}
     show angles

The angle specified in set grid polar is also read and displayed in the units specified by set angles.

set angles also affects the arguments of the machine-defined functions sin(x), cos(x) and tan(x), and the outputs of asin(x), acos(x), atan(x), atan2(x), and arg(x). It has no effect on the arguments of hyperbolic functions or Bessel functions. However, the output arguments of inverse hyperbolic functions of complex arguments are affected; if these functions are used, set angles radians must be in effect to maintain consistency between input and output arguments.

     set angles radians
     print y         #prints {1.16933, 0.154051}
     print asinh(y)  #prints {1.0, 0.1}


     set angles degrees
     print y         #prints {1.16933, 0.154051}
     print asinh(y)  #prints {57.29578, 5.729578}

set arrow

Arbitrary arrows can be placed on a plot using the set arrow command.


     set arrow {<tag>} {from <position>} {to <position>} {{no}head}
               { {linestyle | ls <line_style>}
                 | {linetype | lt <line_type>}
                   {linewidth | lw <line_width} }
     set noarrow {<tag>}
     show arrow

<tag> is an integer that identifies the arrow. If no tag is given, the lowest unused tag value is assigned automatically. The tag can be used to delete or change a specific arrow. To change any attribute of an existing arrow, use the set arrow command with the appropriate tag and specify the parts of the arrow to be changed.

The <position>s are specified by either x,y or x,y,z, and may be preceded by first, second, graph, or screen to select the coordinate system. Unspecified coordinates default to 0. The endpoints can be specified in one of four coordinate systems---first or second axes, graph or screen. See coordinates for details. A coordinate system specifier does not carry over from the "from" position to the "to" position. Arrows outside the screen boundaries are permitted but may cause device errors.

Specifying nohead produces an arrow drawn without a head--a line segment. This gives you yet another way to draw a line segment on the plot. By default, arrows have heads.

The line style may be selected from a user-defined list of line styles (see set linestyle) or may be defined here by providing values for <line_type> (an index from the default list of styles) and/or <line_width> (which is a multiplier for the default width).

Note, however, that if a user-defined line style has been selected, its properties (type and width) cannot be altered merely by issuing another set arrow command with the appropriate index and lt or lw.


To set an arrow pointing from the origin to (1,2) with user-defined style 5, use:

     set arrow to 1,2 ls 5

To set an arrow from bottom left of plotting area to (-5,5,3), and tag the arrow number 3, use:

     set arrow 3 from graph 0,0 to -5,5,3

To change the preceding arrow to end at 1,1,1, without an arrow head and double its width, use:

     set arrow 3 to 1,1,1 nohead lw 2

To draw a vertical line from the bottom to the top of the graph at x=3, use:

     set arrow from 3, graph 0 to 3, graph 1 nohead

To delete arrow number 2, use:

     set noarrow 2

To delete all arrows, use:

     set noarrow

To show all arrows (in tag order), use:

     show arrow

set autoscale

Autoscaling may be set individually on the x, y or z axis or globally on all axes. The default is to autoscale all axes.


     set autoscale {<axes>{min|max}}
     set noautoscale {<axes>{min|max}}
     show autoscale

where <axes> is either x, y, z, x2, y2 or xy. A keyword with min or max appended (this cannot be done with xy) tells gnuplot to autoscale just the minimum or maximum of that axis. If no keyword is given, all axes are autoscaled.

When autoscaling, the axis range is automatically computed and the dependent axis (y for a plot and z for splot) is scaled to include the range of the function or data being plotted.

If autoscaling of the dependent axis (y or z) is not set, the current y or z range is used.

Autoscaling the independent variables (x for plot and x,y for splot) is a request to set the domain to match any data file being plotted. If there are no data files, autoscaling an independent variable has no effect. In other words, in the absence of a data file, functions alone do not affect the x range (or the y range if plotting z = f(x,y)).

Please see set xrange for additional information about ranges.

The behavior of autoscaling remains consistent in parametric mode, (see `set parametric`). However, there are more dependent variables and hence more control over x, y, and z axis scales. In parametric mode, the independent or dummy variable is t for plots and u,v for splots. autoscale in parametric mode, then, controls all ranges (t, u, v, x, y, and z) and allows x, y, and z to be fully autoscaled.

Autoscaling works the same way for polar mode as it does for parametric mode for plot, with the extension that in polar mode set dummy can be used to change the independent variable from t (see set dummy).

When tics are displayed on second axes but no plot has been specified for those axes, x2range and y2range are inherited from xrange and yrange. This is done _before_ xrange and yrange are autoextended to a whole number of tics, which can cause unexpected results.


This sets autoscaling of the y axis (other axes are not affected):

     set autoscale y

This sets autoscaling only for the minimum of the y axis (the maximum of the y axis and the other axes are not affected):

     set autoscale ymin

This sets autoscaling of the x and y axes:

     set autoscale xy

This sets autoscaling of the x, y, z, x2 and y2 axes:

     set autoscale

This disables autoscaling of the x, y, z, x2 and y2 axes:

     set noautoscale

This disables autoscaling of the z axis only:

     set noautoscale z

parametric mode

When in parametric mode (set parametric), the xrange is as fully scalable as the y range. In other words, in parametric mode the x axis can be automatically scaled to fit the range of the parametric function that is being plotted. Of course, the y axis can also be automatically scaled just as in the non-parametric case. If autoscaling on the x axis is not set, the current x range is used.

Data files are plotted the same in parametric and non-parametric mode. However, there is a difference in mixed function and data plots: in non-parametric mode with autoscaled x, the x range of the datafile controls the x range of the functions; in parametric mode it has no influence.

For completeness a last command set autoscale t is accepted. However, the effect of this "scaling" is very minor. When gnuplot determines that the t range would be empty, it makes a small adjustment if autoscaling is true. Otherwise, gnuplot gives an error. Such behavior may, in fact, not be very useful and the command set autoscale t is certainly questionable.

splot extends the above ideas as you would expect. If autoscaling is set, then x, y, and z ranges are computed and each axis scaled to fit the resulting data.

polar mode

When in polar mode (set polar), the xrange and the yrange are both found from the polar coordinates, and thus they can both be automatically scaled. In other words, in polar mode both the x and y axes can be automatically scaled to fit the ranges of the polar function that is being plotted.

When plotting functions in polar mode, the rrange may be autoscaled. When plotting data files in polar mode, the trange may also be autoscaled. Note that if the trange is contained within one quadrant, autoscaling will produce a polar plot of only that single quadrant.

Explicitly setting one or two ranges but not others may lead to unexpected results.

set bar

The set bar command controls the tics at the ends of errorbars.


     set bar {small | large | <size>}
     show bar

small is a synonym for 0.0, and large for 1.0. The default is 1.0 if no size is given.

set bmargin

The command set bmargin sets the size of the bottom margin. Please see set margin for details.

set border

The set border and set noborder commands control the display of the graph borders for the plot and splot commands.


     set border {<integer> { {linestyle | ls <line_style>}
                             | {linetype | lt <line_type> }
                               {linewidth | lw <line_width>} } }
     set noborder
     show border

The borders are encoded in a 12-bit integer: the bottom four bits control the border for plot and the sides of the base for splot; The next four bits control the verticals in splot; the top four bits control the edges on top of the splot. In detail, the <integer> should be the sum of the appropriate entries from the following table:

                       plot border     splot         splot
         Side          splot base    verticals        top
     bottom (south)         1            16           256
     left   (west)          2            32           512
     top    (north)         4            64          1024
     right  (east)          8           128          2048

The default is 31, which is all four sides for plot, and base and z axis for splot.

Using the optional <line_style>, <line_type> and <line_width> specifiers, the way the border lines are drawn can be influenced (limited by what the current terminal driver supports).

Various axes or combinations of axes may be added together in the command.

To have tics on edges other than bottom and left, disable the usual tics and enable the second axes.


Draw all borders:

     set border

Draw only the SOUTHWEST borders:

     set border 3

Draw a complete box around a splot:

     set border 4095

Draw a partial box, omitting the front vertical:

     set border 127+256+512

Draw only the NORTHEAST borders:

     set noxtics; set noytics; set x2tics; set y2tics; set border 12

set boxwidth

The set boxwidth command is used to set the default width of boxes in the boxes and boxerrorbars styles.


     set boxwidth {<width>}
     show boxwidth

If a data file is plotted without the width being specified in the third, fourth, or fifth column (or using entry), or if a function is plotted, the width of each box is set by the set boxwidth command. (If a width is given both in the file and by the set boxwidth command, the one in the file is used.) If the width is not specified in one of these ways, the width of each box will be calculated automatically so that it touches the adjacent boxes. In a four-column data set, the fourth column will be interpreted as the box width unless the width is set to -2.0, in which case the width will be calculated automatically. See set style boxerrorbars for more details.

To set the box width to automatic use the command

     set boxwidth

or, for four-column data,

     set boxwidth -2

The same effect can be achieved with the using keyword in plot:

     plot 'file' using 1:2:3:4:(-2)

set clabel

gnuplot will vary the linetype used for each contour level when clabel is set. When this option on (the default), a legend labels each linestyle with the z level it represents. It is not possible at present to separate the contour labels from the surface key.


     set clabel {'<format>'}
     set noclabel
     show clabel

The default for the format string is %8.3g, which gives three decimal places. This may produce poor label alignment if the key is altered from its default configuration.

The first contour linetype, or only contour linetype when clabel is off, is the surface linetype +1; contour points are the same style as surface points.

See also set contour.

set clip

gnuplot can clip data points and lines that are near the boundaries of a graph.


     set clip <clip-type>
     set noclip <clip-type>
     show clip

Three clip types are supported by gnuplot: points, one, and two. One, two, or all three clip types may be active for a single graph.

The points clip type forces gnuplot to clip (actually, not plot at all) data points that fall within but too close to the boundaries. This is done so that large symbols used for points will not extend outside the boundary lines. Without clipping points near the boundaries, the plot may look bad. Adjusting the x and y ranges may give similar results.

Setting the one clip type causes gnuplot to draw a line segment which has only one of its two endpoints within the graph. Only the in-range portion of the line is drawn. The alternative is to not draw any portion of the line segment.

Some lines may have both endpoints out of range, but pass through the graph. Setting the two clip-type allows the visible portion of these lines to be drawn.

In no case is a line drawn outside the graph.

The defaults are noclip points, clip one, and noclip two.

To check the state of all forms of clipping, use

     show clip

For backward compatibility with older versions, the following forms are also permitted:

     set clip
     set noclip

set clip is synonymous with set clip points; set noclip turns off all three types of clipping.

set cntrparam

set cntrparam controls the generation of contours and their smoothness for a contour plot. show contour displays current settings of cntrparam as well as contour.


     set cntrparam {  {linear | cubicspline | bspline}
                     { points <n>} { order <n> }
                     { levels   auto {<n>} | <n>
                              | discrete <z1> {,<z2>{,<z3>...}}
                              | incremental <start>, <incr> {,<end>}
     show contour

This command has two functions. First, it sets the values of z for which contour points are to be determined (by linear interpolation between data points or function isosamples.) Second, it controls the way contours are drawn between the points determined to be of equal z. <n> should be an integral constant expression and <z1>, <z2> ... any constant expressions. The parameters are:

linear, cubicspline, bspline---Controls type of approximation or interpolation. If linear, then straight line segments connect points of equal z magnitude. If cubicspline, then piecewise-linear contours are interpolated between the same equal z points to form somewhat smoother contours, but which may undulate. If bspline, a guaranteed-smoother curve is drawn, which only approximates the position of the points of equal-z.

points---Eventually all drawings are done with piecewise-linear strokes. This number controls the number of line segments used to approximate the bspline or cubicspline curve. Number of cubicspline or bspline segments (strokes) = points * number of linear segments.

order---Order of the bspline approximation to be used. The bigger this order is, the smoother the resulting contour. (Of course, higher order bspline curves will move further away from the original piecewise linear data.) This option is relevant for bspline mode only. Allowed values are integers in the range from 2 (linear) to 10.

levels--- Selection of contour levels, controlled by auto (default), discrete, incremental, and <n>, number of contour levels, limited to

MAX_DISCRETE_LEVELS as defined in plot.h (30 is standard.)

For auto, <n> specifies a nominal number of levels; the actual number will be adjusted to give simple labels. If the surface is bounded by zmin and zmax, contours will be generated at integer multiples of dz between zmin and zmax, where dz is 1, 2, or 5 times some power of ten (like the step between two tic marks).

For levels discrete, contours will be generated at z = <z1>, <z2> ... as specified; the number of discrete levels sets the number of contour levels. In discrete mode, any set cntrparms levels <n> are ignored.

For incremental, contours are generated at values of z beginning at <start> and increasing by <increment>, until the number of contours is reached. <end> is used to determine the number of contour levels, which will be changed by any subsequent set cntrparam levels <n>.

If the command set cntrparam is given without any arguments specified, the defaults are used: linear, 5 points, order 4, 5 auto levels.


     set cntrparam bspline
     set cntrparam points 7
     set cntrparam order 10

To select levels automatically, 5 if the level increment criteria are met:

     set cntrparam levels auto 5

To specify discrete levels at .1, .37, and .9:

     set cntrparam levels discrete .1,1/exp(1),.9

To specify levels from 0 to 4 with increment 1:

     set cntrparam levels incremental  0,1,4

To set the number of levels to 10 (changing an incremental end or possibly the number of auto levels):

     set cntrparam levels 10

To set the start and increment while retaining the number of levels:

     set cntrparam levels incremental 100,50

See also set contour for control of where the contours are drawn, and `set clabel` for control of the format of the contour labels and linetypes.

set contour

set contour enables contour drawing for surfaces. This option is available for splot only.


     set contour {base | surface | both}
     set nocontour
     show contour

The three options specify where to draw the contours: base draws the contours on the grid base where the x/ytics are placed, surface draws the contours on the surfaces themselves, and both draws the contours on both the base and the surface. If no option is provided, the default is base.

See also set cntrparam for the parameters that affect the drawing of contours, and set clabel for control of labelling of the contours.

The surface can be switched off (see set surface), giving a contour-only graph. Though it is possible to use set size to enlarge the plot to fill the screen, more control over the output format can be obtained by writing the contour information to a file, and rereading it as a 2-d datafile plot:

     set nosurface
     set contour
     set cntrparam ...
     set term table
     set out 'filename'
     splot ...
     set out
     # contour info now in filename
     set term <whatever>
     plot 'filename'

In order to draw contours, the data should be organized as "grid data". In such a file all the points for a single y-isoline are listed, then all the points for the next y-isoline, and so on. A single blank line (a line containing no characters other than blank spaces and a carriage return and/or a line feed) separates one y-isoline from the next. See also splot datafile.

If contours are desired from non-grid data, set dgrid3d can be used to create an appropriate grid. See set dgrid3d for more information.

set data style

The set data style command changes the default plotting style for data plots.


     set data style <style-choice>
     show data style

See set style for the choices. If no choice is given, the choices are listed. show data style shows the current default data plotting style.

set dgrid3d

The set dgrid3d command enables, and can set parameters for, non-grid to grid data mapping.


     set dgrid3d {<row_size>} {,{<col_size>} {,<norm>}}
     set nodgrid3d
     show dgrid3d

By default dgrid3d is disabled. When enabled, 3-d data read from a file are always treated as a scattered data set. A grid with dimensions derived from a bounding box of the scattered data and size as specified by the row/col_size parameters is created for plotting and contouring. The grid is equally spaced in x (rows) and in y (columns); the z values are computed as weighted averages of the scattered points' z values.

The third parameter, norm, controls the weighting: Each data point is weighted inversely by its distance from the grid point raised to the norm power. (Actually, the weights are given by the inverse of dx^norm + dy^norm, where dx and dy are the components of the separation of the grid point from each data point. For some norms that are powers of two, specifically 4, 8, and 16, the computation is optimized by using the Euclidean distance in the weight calculation, (dx^2+dx^2)^norm/2. However, any non-negative integer can be used.)

The closer the data point is to a grid point, the more effect it has on that grid point and the larger the value of norm the less effect more distant data points have on that grid point.

The dgrid3d option is a simple low pass filter that converts scattered data to a grid data set. More sophisticated approaches to this problem exist and should be used to preprocess the data outside gnuplot if this simple solution is found inadequate.

(The z values are found by weighting all data points, not by interpolating between nearby data points; also edge effects may produce unexpected and/or undesired results. In some cases, small norm values produce a grid point reflecting the average of distant data points rather than a local average, while large values of norm may produce "steps" with several grid points having the same value as the closest data point, rather than making a smooth transition between adjacent data points. Some areas of a grid may be filled by extrapolation, to an arbitrary boundary condition. The variables are not normalized; consequently the units used for x and y will affect the relative weights of points in the x and y directions.)


     set dgrid3d 10,10,1     # defaults
     set dgrid3d ,,4

The first specifies that a grid of size 10 by 10 is to be constructed using a norm value of 1 in the weight computation. The second only modifies the norm, changing it to 4.

set dummy

The set dummy command changes the default dummy variable names.


     set dummy {<dummy-var>} {,<dummy-var>}
     show dummy

By default, gnuplot assumes that the independent, or "dummy", variable for the plot command is "t" if in parametric or polar mode, or "x" otherwise. Similarly the independent variables for the splot command are "u" and "v" in parametric mode (splot cannot be used in polar mode), or "x" and "y" otherwise.

It may be more convenient to call a dummy variable by a more physically meaningful or conventional name. For example, when plotting time functions:

     set dummy t
     plot sin(t), cos(t)

At least one dummy variable must be set on the command; set dummy by itself will generate an error message.


     set dummy u,v
     set dummy ,s

The second example sets the second variable to s.

set encoding

The set encoding command selects a character encoding. Valid values are default, which tells a terminal to use its default; iso_8859_1 (known in the PostScript world as ISO-Latin1), which is used on many Unix workstations and with MS-Windows; cp850, for OS/2; and cp437, for MS-DOS.


     set encoding {<value>}
     show encoding

Note that encoding is not supported by all terminal drivers and that the device must be able to produce the desired non-standard characters.

set format

The format of the tic-mark labels can be set with the set format command.


     set format {<axes>} {"<format-string>"}
     set format {<axes>} {'<format-string>'}
     show format

where <axes> is either x, y, z, xy, x2, y2 or nothing (which is the same as xy). The length of the string representing a tic mark (after formatting with 'printf') is restricted to 100 characters. If the format string is omitted, the format will be returned to the default "%g". For LaTeX users, the format "$%g$" is often desirable. If the empty string "" is used, no label will be plotted with each tic, though the tic mark will still be plotted. To eliminate all tic marks, use set noxtics or set noytics.

Newline (\n) is accepted in the format string. Use double-quotes rather than single-quotes to enable such interpretation. See also syntax.

The default format for both axes is "%g", but other formats such as "%.2f" or "%3.0em" are often desirable. Anything accepted by 'printf' when given a double precision number, and accepted by the terminal, will work. Some other options have been added. If the format string looks like a floating point format, then gnuplot tries to construct a reasonable format.

Characters not preceded by "%" are printed verbatim. Thus you can include spaces and labels in your format string, such as "%g m", which will put " m" after each number. If you want "%" itself, double it: "%g %%".

See also set xtics for more information about tic labels.

format specifiers

The acceptable formats (if not in time/date mode) are:

     Format       Explanation
     %f           floating point notation
     %e or %E     exponential notation; an "e" or "E" before the power
     %g or %G     the shorter of %e (or %E) and %f
     %x or %X     hex
     %o or %O     octal
     %t           mantissa to base 10
     %l           mantissa to base of current logscale
     %s           mantissa to base of current logscale; scientific power
     %T           power to base 10
     %L           power to base of current logscale
     %S           scientific power
     %c           character replacement for scientific power
     %P           multiple of pi

A 'scientific' power is one such that the exponent is a multiple of three. Character replacement of scientific powers ("%c") has been implemented for powers in the range -18 to +18. For numbers outside of this range the format reverts to exponential.

Other acceptable modifiers (which come after the "%" but before the format specifier) are "-", which left-justifies the number; "+", which forces all numbers to be explicitly signed; "#", which places a decimal point after floats that have only zeroes following the decimal point; a positive integer, which defines the field width; "0" (the digit, not the letter) immediately preceding the field width, which indicates that leading zeroes are to be used instead of leading blanks; and a decimal point followed by a non-negative integer, which defines the precision (the minimum number of digits of an integer, or the number of digits following the decimal point of a float).

Some releases of 'printf' may not support all of these modifiers but may also support others; in case of doubt, check the appropriate documentation and then experiment.


     set format y "%t"; set ytics (5,10)          # "5.0" and "1.0"
     set format y "%s"; set ytics (500,1000)      # "500" and "1.0"
     set format y "+-12.3f"; set ytics(12345)     # "+12345.000  "
     set format y "%.2t*10^%+03T"; set ytic(12345)# "1.23*10^+04"
     set format y "%s*10^{%S}"; set ytic(12345)   # "12.345*10^{3}"
     set format y "%s %cg"; set ytic(12345)       # "12.345 kg"
     set format y "%.0P pi"; set ytic(6.283185)   # "2 pi"
     set format y "%.0P%%"; set ytic(50)          # "50%"
     set log y 2; set format y '%l'; set ytics (1,2,3)
     #displays "1.0", "1.0" and "1.5" (since 3 is 1.5 * 2^1)

There are some problem cases that arise when numbers like 9.999 are printed with a format that requires both rounding and a power.

If the data type for the axis is time/date, the format string must contain valid codes for the 'strftime' function (outside of gnuplot, type "man strftime"). See set timefmt for a list of the allowed input format codes.

time/date specifiers

In time/date mode, the acceptable formats are:

     Format       Explanation
     %a           abbreviated name of day of the week
     %A           full name of day of the week
     %b or %h     abbreviated name of the month
     %B           full name of the month
     %d           day of the month, 1--31
     %D           shorthand for "%m/%d/%y"
     %H or %k     hour, 0--24
     %I or %l     hour, 0--12
     %j           day of the year, 1--366
     %m           month, 1--12
     %M           minute, 0--60
     %p           "am" or "pm"
     %r           shorthand for "%I:%M:%S %p"
     %R           shorthand for %H:%M"
     %S           second, 0--60
     %T           shorthand for "%H:%M:%S"
     %U           week of the year (week starts on Sunday)
     %w           day of the week, 0--6 (Sunday = 0)
     %W           week of the year (week starts on Monday)
     %y           year, 0-99
     %Y           year, 4-digit

Except for the non-numerical formats, these may be preceded by a "0" ("zero", not "oh") to pad the field length with leading zeroes, and a positive digit, to define the minimum field width (which will be overridden if the specified width is not large enough to contain the number). There is a 24-character limit to the length of the printed text; longer strings will be truncated.


Suppose the text is "76/12/25 23:11:11". Then

     set format x                 # defaults to "12/25/76" \n "23:11"
     set format x "%A, %d %b %Y"  # "Saturday, 25 Dec 1976"
     set format x "%r %d"         # "11:11:11 pm 12/25/76"

Suppose the text is "98/07/06 05:04:03". Then

     set format x "%1y/%2m/%3d %01H:%02M:%03S"  # "98/ 7/  6 5:04:003"

set function style

The set function style command changes the default plotting style for function plots.


     set function style <style-choice>
     show function style

See set style for the choices. If no choice is given, the choices are listed. show function style shows the current default function plotting style.

set functions

The show functions command lists all user-defined functions and their definitions.


     show functions

For information about the definition and usage of functions in gnuplot, please see expressions.

set grid

The set grid command allows grid lines to be drawn on the plot.


     set grid {{no}{m}xtics} {{no}{m}ytics} {{no}{m}ztics}
              {{no}{m}x2tics} {{no}{m}y2tics}
              {polar {<angle>}}
              { {linestyle <major_linestyle>}
                | {linetype | lt <major_linetype>}
                  {linewidth | lw <major_linewidth>}
                { , {linestyle | ls <minor_linestyle>}
                    | {linetype | lt <minor_linetype>}
                      {linewidth | lw <minor_linewidth>} } }
     set nogrid
     show grid

The grid can be enabled and disabled for the major and/or minor tic marks on any axis, and the linetype and linewidth can be specified for major and minor grid lines, also via a predefined linestyle, as far as the active terminal driver supports this.

Additionally, a polar grid can be selected for 2-d plots--circles are drawn to intersect the selected tics, and radial lines are drawn at definable intervals. (The interval is given in degrees or radians ,depending on the set angles setting.) Note that a polar grid is no longer automatically generated in polar mode.

The pertinent tics must be enabled before set grid can draw them; gnuplot will quietly ignore instructions to draw grid lines at non-existent tics, but they will appear if the tics are subsequently enabled.

If no linetype is specified for the minor gridlines, the same linetype as the major gridlines is used. The default polar angle is 30 degrees.

Z grid lines are drawn on the back of the plot. This looks better if a partial box is drawn around the plot--see set border.

set hidden3d

The set hidden3d command enables hidden line removal for surface plotting (see splot). Some optional features of the underlying algorithm can also be controlled using this command.


     set hidden3d {defaults} |
                  { {{offset <offset>} | {nooffset}}
                    {trianglepattern <bitpattern>}
                    {{undefined <level>} | {noundefined}}
                    {{no}bentover} }
     set nohidden3d
     show hidden3d

In contrast to the usual display in gnuplot, hidden line removal actually treats the given function or data grids as real surfaces that can't be seen through, so parts behind the surface will be hidden by it. For this to be possible, the surface needs to have 'grid structure' (see splot datafile about this), and it has to be drawn with lines or with linespoints.

When hidden3d is set, both the hidden portion of the surface and possibly its contours drawn on the base (see set contour) as well as the grid will be hidden. Each surface has its hidden parts removed with respect to itself and to other surfaces, if more than one surface is plotted. Contours drawn on the surface (set contour surface) don't work. Labels and arrows are always visible and are unaffected. The key is also never hidden by the surface.

Functions are evaluated at isoline intersections. The algorithm interpolates linearly between function points or data points when determining the visible line segments. This means that the appearance of a function may be different when plotted with hidden3d than when plotted with nohidden3d because in the latter case functions are evaluated at each sample. Please see `set samples and set isosamples` for discussion of the difference.

The algorithm used to remove the hidden parts of the surfaces has some additional features controllable by this command. Specifying defaults will set them all to their default settings, as detailed below. If defaults is not given, only explicitly specified options will be influenced: all others will keep their previous values, so you can turn on/off hidden line removal via set {no}hidden3d, without modifying the set of options you chose.

The first option, offset, influences the linestyle used for lines on the 'back' side. Normally, they are drawn in a linestyle one index number higher than the one used for the front, to make the two sides of the surface distinguishable. You can specify a different line style offset to add instead of the default 1, by offset <offset>. Option nooffset stands for offset 0, making the two sides of the surface use the same linestyle.

Next comes the option trianglepattern <bitpattern>. <bitpattern> must be a number between 0 and 7, interpreted as a bit pattern. Each bit determines the visibility of one edge of the triangles each surface is split up into. Bit 0 is for the 'horizontal' edges of the grid, Bit 1 for the 'vertical' ones, and Bit 2 for the diagonals that split each cell of the original grid into two triangles. The default pattern is 3, making all horizontal and vertical lines visible, but not the diagonals. You may want to choose 7 to see those diagonals as well.

The undefined <level> option lets you decide what the algorithm is to do with data points that are undefined (missing data, or undefined function values), or exceed the given x-, y- or z-ranges. Such points can either be plotted nevertheless, or taken out of the input data set. All surface elements touching a point that is taken out will be taken out as well, thus creating a hole in the surface. If <level> = 3, equivalent to option noundefined, no points will be thrown away at all. This may produce all kinds of problems elsewhere, so you should avoid this. <level> = 2 will throw away undefined points, but keep the out-of-range ones. <level> = 1, the default, will get rid of out-of-range points as well.

By specifying noaltdiagonal, you can override the default handling of a special case can occur if undefined is active (i.e. <level> is not 3). Each cell of the grid-structured input surface will be divided in two triangles along one of its diagonals. Normally, all these diagonals have the same orientation relative to the grid. If exactly one of the four cell corners is excluded by the undefined handler, and this is on the usual diagonal, both triangles will be excluded. However if the default setting of altdiagonal is active, the other diagonal will be chosen for this cell instead, minimizing the size of the hole in the surface.

The bentover option controls what happens to another special case, this time in conjunction with the trianglepattern. For rather crumply surfaces, it can happen that the two triangles a surface cell is divided into are seen from opposite sides (i.e. the original quadrangle is 'bent over'), as illustrated in the following ASCII art:

   original quadrangle:  A--B      displayed quadrangle:     |\   |
     ("set view 0,0")    | /|    ("set view 75,75" perhaps)  | \  |
                         |/ |                                |  \ |
                         C--D                                |   \|
                                                             A    D

If the diagonal edges of the surface cells aren't generally made visible by bit 2 of the <bitpattern> there, the edge CB above wouldn't be drawn at all, normally, making the resulting display hard to understand. Therefore, the default option of bentover will turn it visible in this case. If you don't want that, you may choose nobentover instead.

set isosamples

The isoline density (grid) for plotting functions as surfaces may be changed by the set isosamples command.


     set isosamples <iso_1> {,<iso_2>}
     show isosamples

Each function surface plot will have <iso_1> iso-u lines and <iso_2> iso-v lines. If you only specify <iso_1>, <iso_2> will be set to the same value as <iso_1>. By default, sampling is set to 10 isolines per u or v axis. A higher sampling rate will produce more accurate plots, but will take longer. These parameters have no effect on data file plotting.

An isoline is a curve parameterized by one of the surface parameters while the other surface parameter is fixed. Isolines provide a simple means to display a surface. By fixing the u parameter of surface s(u,v), the iso-u lines of the form c(v) = s(u0,v) are produced, and by fixing the v parameter, the iso-v lines of the form c(u) = s(u,v0) are produced.

When a function surface plot is being done without the removal of hidden lines, set samples controls the number of points sampled along each isoline; see set samples and set hidden3d. The contour algorithm assumes that a function sample occurs at each isoline intersection, so change in samples as well as isosamples may be desired when changing the resolution of a function surface/contour.

set key

The set key enables a key (or legend) describing plots on a plot.

The contents of the key, i.e., the names given to each plotted data set and function and samples of the lines and/or symbols used to represent them, are determined by the title and with options of the {s}plot command. Please see plot title and plot with for more information.


     set key {  left | right | top | bottom | outside | below
              | <position>}
             {Left | Right} {{no}reverse}
             {samplen <sample_length>} {spacing <vertical_spacing>}
             {width <width_increment>}
             {title "<text>"}
             {{no}box { {linestyle | ls <line_style>}
                        | {linetype | lt <line_type>}
                          {linewidth | lw <line_width>}}}
     set nokey
     show key

By default the key is placed in the upper right corner of the graph. The keywords left, right, top, bottom, outside and below may be used to place the key in the other corners inside the graph or to the right (outside) or below the graph. They may be given alone or combined.

Justification of the labels within the key is controlled by Left or Right (default is Right). The text and sample can be reversed (reverse) and a box can be drawn around the key (box {...}) in a specified linetype and linewidth, or a user-defined linestyle. Note that not all terminal drivers support linewidth selection, though.

The length of the sample line can be controlled by samplen. The sample length is computed as the sum of the tic length and <sample_length> times the character width. samplen also affects the positions of point samples in the key since these are drawn at the midpoint of the sample line, even if it is not drawn. <sample_length> must be an integer.

The vertical spacing between lines is controlled by spacing. The spacing is set equal to the product of the pointsize, the vertical tic size, and <vertical_spacing>. The program will guarantee that the vertical spacing is no smaller than the character height.

The <width_increment> is a number of character widths to be added to or subtracted from the length of the string. This is useful only when you are putting a box around the key and you are using control characters in the text. gnuplot simply counts the number of characters in the string when computing the box width; this allows you to correct it.

A title can be put on the key (title "<text>")---see also syntax for the distinction between text in single- or double-quotes. The key title uses the same justification as do the plot titles.

The defaults for set key are right, top, Right, noreverse, `samplen 4, spacing 1.25, title "", and nobox`. The default <linetype> is the same as that used for the plot borders. Entering set key with no options returns the key to its default configuration.

The <position> can be a simple x,y,z as in previous versions, but these can be preceded by one of four keywords (first, second, graph, screen) which selects the coordinate system in which the position is specified. See coordinates for more details.

The key is drawn as a sequence of lines, with one plot described on each line. On the right-hand side (or the left-hand side, if reverse is selected) of each line is a representation that attempts to mimic the way the curve is plotted. On the other side of each line is the text description (the line title), obtained from the plot command. The lines are vertically arranged so that an imaginary straight line divides the left- and right-hand sides of the key. It is the coordinates of the top of this line that are specified with the set key command. In a plot, only the x and y coordinates are used to specify the line position. For a splot, x, y and z are all used as a 3-d location mapped using the same mapping as the graph itself to form the required 2-d screen position of the imaginary line.

Some or all of the key may be outside of the graph boundary, although this may interfere with other labels and may cause an error on some devices. If you use the keywords outside or below, gnuplot makes space for the keys and the graph becomes smaller. Putting keys outside to the right, they occupy as few columns as possible, and putting them below, as many columns as possible (depending of the length of the labels), thus stealing as little space from the graph as possible.

When using the TeX or PostScript drivers, or similar drivers where formatting information is embedded in the string, gnuplot is unable to calculate correctly the width of the string for key positioning. If the key is to be positioned at the left, it may be convenient to use the combination `set key left Left reverse`. The box and gap in the grid will be the width of the literal string.

If splot is being used to draw contours, the contour labels will be listed in the key. If the alignment of these labels is poor or a different number of decimal places is desired, the label format can be specified. See `set clabel` for details.


This places the key at the default location:

     set key

This disables the key:

     set nokey

This places a key at coordinates 2,3.5,2 in the default (first) coordinate system:

     set key 2,3.5,2

This places the key below the graph:

     set key below

This places the key in the bottom left corner, left-justifies the text, gives it a title, and draws a box around it in linetype 3:

     set key left bottom Left title 'Legend' box 3

set label

Arbitrary labels can be placed on the plot using the set label command.


     set label {<tag>} {"<label_text>"} {at <position>}
               {<justification>} {{no}rotate} {font "<name><,size>"}
     set nolabel {<tag>}
     show label

The <position> is specified by either x,y or x,y,z, and may be preceded by first, second, graph, or screen to select the coordinate system. See coordinates for details.

The tag is an integer that is used to identify the label. If no <tag> is given, the lowest unused tag value is assigned automatically. The tag can be used to delete or modify a specific label. To change any attribute of an existing label, use the set label command with the appropriate tag, and specify the parts of the label to be changed.

By default, the text is placed flush left against the point x,y,z. To adjust the way the label is positioned with respect to the point x,y,z, add the parameter <justification>, which may be left, right or center, indicating that the point is to be at the left, right or center of the text. Labels outside the plotted boundaries are permitted but may interfere with axis labels or other text.

If rotate is given, the label is written vertically (if the terminal can do so, of course).

If one (or more) axis is timeseries, the appropriate coordinate should be given as a quoted time string according to the timefmt format string. See set xdata and set timefmt.

The EEPIC, Imagen, LaTeX, and TPIC drivers allow \\ in a string to specify a newline.


To set a label at (1,2) to "y=x", use:

     set label "y=x" at 1,2

To set a Sigma of size 24, from the Symbol font set, at the center of the graph, use:

     set label "S" at graph 0.5,0.5 center font "Symbol,24"

To set a label "y=x^2" with the right of the text at (2,3,4), and tag the label as number 3, use:

     set label 3 "y=x^2" at 2,3,4 right

To change the preceding label to center justification, use:

     set label 3 center

To delete label number 2, use:

     set nolabel 2

To delete all labels, use:

     set nolabel

To show all labels (in tag order), use:

     show label

To set a label on a graph with a timeseries on the x axis, use, for example:

     set timefmt "%d/%m/%y,%H:%M"
     set label "Harvest" at "25/8/93",1

set linestyle

Each terminal has a default set of line and point types, which can be seen by using the command test. set linestyle defines a set of line types and widths and point types and sizes so that you can refer to them later by an index instead of repeating all the information at each invocation.


     set linestyle <index> {linetype | lt <line_type>}
                           {linewidth | lw <line_width>}
                           {pointtype | pt <point_type>}
                           {pointsize | ps <point_size>}
     set nolinestyle
     show linestyle

The line and point types are taken from the default types for the terminal currently in use. The line width and point size are multipliers for the default width and size (but note that <point_size> here is unaffected by the multiplier given on 'set pointsize').

The defaults for the line and point types is the index. The defaults for the width and size are both unity.

Linestyles created by this mechanism do not replace the default styles; both may be used.

Not all terminals support the linewidth and pointsize features; if not supported, the option will be ignored.

Note that this feature is not completely implemented; linestyles defined by this mechanism may be used with 'plot', 'splot', 'replot', and 'set arrow', but not by other commands that allow the default index to be used, such as 'set grid'.

Example: Suppose that the default lines for indices 1, 2, and 3 are red, green, and blue, respectively, and the default point shapes for the same indices are a square, a cross, and a triangle, respectively. Then

     set linestyle 1 lt 2 lw 2 pt 3 ps 0.5

defines a new linestyle that is green and twice the default width and a new pointstyle that is a half-sized triangle. The commands

     set function style lines
     plot f(x) lt 3, g(x) ls 1

will create a plot of f(x) using the default blue line and a plot of g(x) using the user-defined wide green line. Similarly the commands

     set function style linespoints
     plot p(x) lt 1 pt 3, q(x) ls 1

will create a plot of f(x) using the default triangles connected by a red line and q(x) using small triangles connected by a green line.

set lmargin

The command set lmargin sets the size of the left margin. Please see set margin for details.

set locale

The locale setting determines the language with which {x,y,z}{d,m}tics will write the days and months.


     set locale {"<locale>"}

<locale> may be any language designation acceptable to your installation. See your system documentation for the available options. The default value is determined from the LANG environment variable.

set logscale

Log scaling may be set on the x, y, z, x2 and/or y2 axes.


     set logscale <axes> <base>
     set nologscale <axes>
     show logscale

where <axes> may be any combinations of x, y, and z, in any order, or x2 or y2 and where <base> is the base of the log scaling. If <base> is not given, then 10 is assumed. If <axes> is not given, then all axes are assumed. set nologscale turns off log scaling for the specified axes.


To enable log scaling in both x and z axes:

     set logscale xz

To enable scaling log base 2 of the y axis:

     set logscale y 2

To disable z axis log scaling:

     set nologscale z

set mapping

If data are provided to splot in spherical or cylindrical coordinates, the set mapping command should be used to instruct gnuplot how to interpret them.


     set mapping {cartesian | spherical | cylindrical}

A cartesian coordinate system is used by default.

For a spherical coordinate system, the data occupy two or three columns (or using entries). The first two are interpreted as the polar and azimuthal angles theta and phi (in the units specified by set angles). The radius r is taken from the third column if there is one, or is set to unity if there is no third column. The mapping is:

     x = r * cos(theta) * cos(phi)
     y = r * sin(theta) * cos(phi)
     z = r * sin(phi)

Note that this is a "geographic" spherical system, rather than a "polar" one.

For a cylindrical coordinate system, the data again occupy two or three columns. The first two are interpreted as theta (in the units specified by set angles) and z. The radius is either taken from the third column or set to unity, as in the spherical case. The mapping is:

     x = r * cos(theta)
     y = r * sin(theta)
     z = z

The effects of mapping can be duplicated with the using filter on the splot command, but mapping may be more convenient if many data files are to be processed. However even if mapping is used, using may still be necessary if the data in the file are not in the required order.

mapping has no effect on plot.

set margin

Normally the margins of a plot are automatically calculated based on tics and axis labels (and the size of the graph correspondingly adjusted.) These computed values can be overridden by the set margin commands. show margin shows the current settings.


     set bmargin {<margin>}
     set lmargin {<margin>}
     set rmargin {<margin>}
     set tmargin {<margin>}
     show margin

The units of <margin> are character heights or widths, as appropriate. A positive value defines the absolute size of the margin. A negative value (or none) causes gnuplot to revert to the computed value.

set missing

The set missing command allows you to tell gnuplot what character is used in a data file to denote missing data.


     set missing {"<character>"}
     show missing


     set missing "?"

would mean that, when plotting a file containing

        1 1
        2 ?
        3 2

the middle line would be ignored.

There is no default character for missing.

set multiplot

The command set multiplot places gnuplot in the multiplot mode, in which several plots are placed on the same page, window, or screen.


     set multiplot
     set nomultiplot

For some terminals, no plot is displayed until the command set nomultiplot is given, which causes the entire page to be drawn and then returns gnuplot to its normal single-plot mode. For other terminals, each separate plot command produces a plot, but the screen may not be cleared between plots.

Any labels or arrows that have been defined will be drawn for each plot according to the current size and origin (unless their coordinates are defined in the screen system). Just about everything else that can be set is applied to each plot, too. If you want something to appear only once on the page, for instance a single time stamp, you'll need to put a `set time/set notime pair around one of the plot, splot or replot` commands within the set multiplot/set nomultiplot block.

The commands set origin and set size must be used to correctly position each plot; see set origin and set size for details of their usage.


     set size 0.7,0.7
     set origin 0.1,0.1
     set multiplot
     set size 0.4,0.4
     set origin 0.1,0.1
     plot sin(x)
     set size 0.2,0.2
     set origin 0.5,0.5
     plot cos(x)
     set nomultiplot

displays a plot of cos(x) stacked above a plot of sin(x). Note the initial set size and set origin. While these are not always required, their inclusion is recommended. Some terminal drivers require that bounding box information be available before any plots can be made, and the form given above guarantees that the bounding box will include the entire plot array rather than just the bounding box of the first plot.

set size and set origin refer to the entire plotting area used for each plot. If you want to have the axes themselves line up, you can guarantee that the margins are the same size with the set margin commands. See set margin for their use. Note that the margin settings are absolute, in character units, so the appearance of the graph in the remaining space will depend on the screen size of the display device, e.g., perhaps quite different on a video display and a printer.

set mx2tics

Minor tic marks along the x2 (top) axis are controlled by set mx2tics. Please see set mxtics.

set mxtics

Minor tic marks along the x axis are controlled by set mxtics. They can be turned off with set nomxtics. Similar commands control minor tics along the other axes.


     set mxtics {<freq> | default}
     set nomxtics
     show mxtics

The same syntax applies to mytics, mztics, mx2tics and my2tics.

<freq> is the number of sub-intervals (NOT the number of minor tics) between major tics (ten is the default for a linear axis, so there are nine minor tics between major tics). Selecting default will return the number of minor ticks to its default value.

If the axis is logarithmic, the number of sub-intervals will be set to a reasonable number by default (based upon the length of a decade). This will be overridden if <freq> is given. However the usual minor tics (2, 3, ..., 8, 9 between 1 and 10, for example) are obtained by setting <freq> to 10, even though there are but nine sub-intervals.

Minor tics can be used only with uniformly spaced major tics. Since major tics can be placed arbitrarily by set {x|x2|y|y2|z}tics, minor tics cannot be used if major tics are explicitly set.

By default, minor tics are off for linear axes and on for logarithmic axes. They inherit the settings for axis|border and {no}mirror specified for the major tics. Please see set xtics for information about these.

set my2tics

Minor tic marks along the y2 (right-hand) axis are controlled by `set my2tics. Please see set mxtics`.

set mytics

Minor tic marks along the y axis are controlled by set mytics. Please see set mxtics.

set mztics

Minor tic marks along the z axis are controlled by set mztics. Please see set mxtics.

set offsets

Offsets provide a mechanism to put a boundary around the data inside of an autoscaled graph.


     set offsets <left>, <right>, <top>, <bottom>
     set nooffsets
     show offsets

Each offset may be a constant or an expression. Each defaults to 0. Left and right offsets are given in units of the x axis, top and bottom offsets in units of the y axis. A positive offset expands the graph in the specified direction, e.g., a positive bottom offset makes ymin more negative. Negative offsets, while permitted, can have unexpected interactions with autoscaling and clipping.

Offsets are ignored in splots.


     set offsets 0, 0, 2, 2
     plot sin(x)

This graph of sin(x) will have a y range [-3:3] because the function will be autoscaled to [-1:1] and the vertical offsets are each two.

set origin

The set origin command is used to specify the origin of a plotting surface (i.e., the graph and its margins) on the screen. The coordinates are given in the screen coordinate system (see coordinates for information about this system).


     set origin <x-origin>,<y-origin>

set output

By default, screens are displayed to the standard output. The set output command redirects the display to the specified file or device.


     set output {"<filename>"}
     show output

The filename must be enclosed in quotes. If the filename is omitted, any output file opened by a previous invocation of set output will be closed and new output will be sent to STDOUT. (If you give the command `set output "STDOUT"`, your output may be sent to a file named "STDOUT"! ["May be", not "will be", because some terminals, like x11, ignore set output.])

MSDOS users should note that the \ character has special significance in double-quoted strings, so single-quotes should be used for filenames in different directories.

When both set terminal and set output are used together, it is safest to give set terminal first, because some terminals set a flag which is needed in some operating systems. This would be the case, for example, if the operating system needs to know whether or not a file is to be formatted in order to open it properly.

On machines with popen functions (Unix), output can be piped through a shell command if the first non-whitespace character of the filename is '|'. For instance,

     set output "|lpr -Plaser filename"
     set output "|lp -dlaser filename"

On MSDOS machines, set output "PRN" will direct the output to the default printer. On VMS, output can be sent directly to any spooled device. It is also possible to send the output to DECnet transparent tasks, which allows some flexibility.

set parametric

The set parametric command changes the meaning of plot (splot) from normal functions to parametric functions. The command set noparametric restores the plotting style to normal, single-valued expression plotting.


     set parametric
     set noparametric
     show parametric

For 2-d plotting, a parametric function is determined by a pair of parametric functions operating on a parameter. An example of a 2-d parametric function would be plot sin(t),cos(t), which draws a circle (if the aspect ratio is set correctly--see set size). gnuplot will display an error message if both functions are not provided for a parametric plot.

For 3-d plotting, the surface is described as x=f(u,v), y=g(u,v), z=h(u,v). Therefore a triplet of functions is required. An example of a 3-d parametric function would be cos(u)*cos(v),cos(u)*sin(v),sin(u), which draws a sphere. gnuplot will display an error message if all three functions are not provided for a parametric splot.

The total set of possible plots is a superset of the simple f(x) style plots, since the two functions can describe the x and y values to be computed separately. In fact, plots of the type t,f(t) are equivalent to those produced with f(x) because the x values are computed using the identity function. Similarly, 3-d plots of the type u,v,f(u,v) are equivalent to f(x,y).

Note that the order the parametric functions are specified is xfunction, yfunction (and zfunction) and that each operates over the common parametric domain.

Also, the set parametric function implies a new range of values. Whereas the normal f(x) and f(x,y) style plotting assume an xrange and yrange (and zrange), the parametric mode additionally specifies a trange, urange, and vrange. These ranges may be set directly with set trange, set urange, and set vrange, or by specifying the range on the plot or splot commands. Currently the default range for these parametric variables is [-5:5]. Setting the ranges to something more meaningful is expected.

set pointsize

The set pointsize command scales the size of the points used in plots.


     set pointsize <multiplier>
     show pointsize

The default is a multiplier of 1.0. Larger pointsizes may be useful to make points more visible in bitmapped graphics.

The pointsize of a single plot may be changed on the plot command. See plot with for details.

Please note that the pointsize setting is not supported by all terminal types.

set polar

The set polar command changes the meaning of the plot from rectangular coordinates to polar coordinates.


     set polar
     set nopolar
     show polar

There have been changes made to polar mode in version 3.7, so that scripts for gnuplot versions 3.5 and earlier will require modification. The main change is that the dummy variable t is used for the angle so that the x and y ranges can be controlled independently. Other changes are: 1) tics are no longer put along the zero axes automatically ---use set xtics axis nomirror; set ytics axis nomirror; 2) the grid, if selected, is not automatically polar ---use set grid polar; 3) the grid is not labelled with angles ---use set label as necessary.

In polar coordinates, the dummy variable (t) is an angle. The default range of t is [0:2*pi], or, if degree units have been selected, to [0:360] (see set angles).

The command set nopolar changes the meaning of the plot back to the default rectangular coordinate system.

The set polar command is not supported for splots. See the set mapping command for similar functionality for splots.

While in polar coordinates the meaning of an expression in t is really r = f(t), where t is an angle of rotation. The trange controls the domain (the angle) of the function, and the x and y ranges control the range of the graph in the x and y directions. Each of these ranges, as well as the rrange, may be autoscaled or set explicitly. See set xrange for details of all the set range commands.


     set polar
     plot t*sin(t)
     plot [-2*pi:2*pi] [-3:3] [-3:3] t*sin(t)

The first plot uses the default polar angular domain of 0 to 2*pi. The radius and the size of the graph are scaled automatically. The second plot expands the domain, and restricts the size of the graph to [-3:3] in both directions.

You may want to set size square to have gnuplot try to make the aspect ratio equal to unity, so that circles look circular.

set rmargin

The command set rmargin sets the size of the right margin. Please see set margin for details.

set rrange

The set rrange command sets the range of the radial coordinate for a graph in polar mode. Please see set xrange for details.

set samples

The sampling rate of functions, or for interpolating data, may be changed by the set samples command.


     set samples <samples_1> {,<samples_2>}
     show samples

By default, sampling is set to 100 points. A higher sampling rate will produce more accurate plots, but will take longer. This parameter has no effect on data file plotting unless one of the interpolation/approximation options is used. See plot smooth re 2-d data and set cntrparam and set dgrid3d re 3-d data.

When a 2-d graph is being done, only the value of <samples_1> is relevant.

When a surface plot is being done without the removal of hidden lines, the value of samples specifies the number of samples that are to be evaluated for the isolines. Each iso-v line will have <sample_1> samples and each iso-u line will have <sample_2> samples. If you only specify <samples_1>, <samples_2> will be set to the same value as <samples_1>. See also `set isosamples`.

set size

The set size command scales the displayed size of the plot.


     set size {{no}square | ratio <r> | noratio} {<xscale>,<yscale>}
     show size

The <xscale> and <yscale> values are the scaling factors for the size of the plot, which includes the graph and the margins.

ratio causes gnuplot to try to create a graph with an aspect ratio of <r> (the ratio of the y-axis length to the x-axis length) within the portion of the plot specified by <xscale> and <yscale>.

The meaning of a negative value for <r> is different. If <r>=-1, gnuplot tries to set the scales so that the unit has the same length on both the x and y axes (suitable for geographical data, for instance). If <r>=-2, the unit on y has twice the length of the unit on x, and so on.

The success of gnuplot in producing the requested aspect ratio depends on the terminal selected. The graph area will be the largest rectangle of aspect ratio <r> that will fit into the specified portion of the output (leaving adequate margins, of course).

square is a synonym for ratio 1.

Both noratio and nosquare return the graph to the default aspect ratio of the terminal, but do not return <xscale> or <yscale> to their default values (1.0).

ratio and square have no effect on 3-d plots.

set size is relative to the default size, which differs from terminal to terminal. Since gnuplot fills as much of the available plotting area as possible by default, it is safer to use set size to decrease the size of a plot than to increase it. See set terminal for the default sizes.

On some terminals, changing the size of the plot will result in text being misplaced.


To set the size to normal size use:

     set size 1,1

To make the graph half size and square use:

     set size square 0.5,0.5

To make the graph twice as high as wide use:

     set size ratio 2

set style

Default styles are chosen with the set function style and set data style commands. See plot with for information about how to override the default plotting style for individual functions and data sets.


     set function style <style>
     set data style <style>
     show function style
     show data style

The types used for all line and point styles (i.e., solid, dash-dot, color, etc. for lines; circles, squares, crosses, etc. for points) will be either those specified on the plot or splot command or will be chosen sequentially from the types available to the terminal in use. Use the command test to see what is available.

None of the styles requiring more than two columns of information (e.g., errorbars) can be used with splots or function plots. Neither boxes nor any of the steps styles can be used with splots. If an inappropriate style is specified, it will be changed to points.

For 2-d data with more than two columns, gnuplot is picky about the allowed errorbar styles. The using option on the plot command can be used to set up the correct columns for the style you want. (In this discussion, "column" will be used to refer both to a column in the data file and an entry in the using list.)

For three columns, only xerrorbars, yerrorbars (or errorbars), boxes, and boxerrorbars are allowed. If another plot style is used, the style will be changed to yerrorbars. The boxerrorbars style will calculate the boxwidth automatically.

For four columns, only xerrorbars, yerrorbars (or errorbars), xyerrorbars, boxxyerrorbars, and boxerrorbars are allowed. An illegal style will be changed to yerrorbars.

Five-column data allow only the boxerrorbars, financebars, and candlesticks styles. (The last two of these are primarily used for plots of financial prices.) An illegal style will be changed to boxerrorbars before plotting.

Six- and seven-column data only allow the xyerrorbars and boxxyerrorbars styles. Illegal styles will be changed to xyerrorbars before plotting.

For more information about error bars, please see plot errorbars.


The boxerrorbars style is only relevant to 2-d data plotting. It is a combination of the boxes and yerrorbars styles. The boxwidth will come from the fourth column if the y errors are in the form of "ydelta" and the boxwidth was not previously set equal to -2.0 (set boxwidth -2.0) or from the fifth column if the y errors are in the form of "ylow yhigh". The special case boxwidth = -2.0 is for four-column data with y errors in the form "ylow yhigh". In this case the boxwidth will be calculated so that each box touches the adjacent boxes. The width will also be calculated in cases where three-column data are used.

The box height is determined from the y error in the same way as it is for the yerrorbars style--either from y-ydelta to y+ydelta or from ylow to yhigh, depending on how many data columns are provided.


The boxes style is only relevant to 2-d plotting. It draws a box centered about the given x coordinate from the x axis (not the graph border) to the given y coordinate. The width of the box is obtained in one of three ways. If it is a data plot and the data file has a third column, this will be used to set the width of the box. If not, if a width has been set using the `set boxwidth` command, this will be used. If neither of these is available, the width of each box will be calculated automatically so that it touches the adjacent boxes.


The boxxyerrorbars style is only relevant to 2-d data plotting. It is a combination of the boxes and xyerrorbars styles.

The box width and height are determined from the x and y errors in the same way as they are for the xyerrorbars style--either from xlow to xhigh and from ylow to yhigh, or from x-xdelta to x+xdelta and from y-ydelta to y+ydelta , depending on how many data columns are provided.


The candlesticks style is only relevant for 2-d data plotting of financial data. Five columns of data are required; in order, these should be the x coordinate (most likely a date) and the opening, low, high, and closing prices. The symbol is an open rectangle, centered horizontally at the x coordinate and limited vertically by the opening and closing prices. A vertical line segment at the x coordinate extends up from the top of the rectangle to the high price and another down to the low. The width of the rectangle may be changed by set bar. The symbol will be unchanged if the low and high prices are interchanged or if the opening and closing prices are interchanged. See set bar and financebars.


The dots style plots a tiny dot at each point; this is useful for scatter plots with many points.


The financebars style is only relevant for 2-d data plotting of financial data. Five columns of data are required; in order, these should be the x coordinate (most likely a date) and the opening, low, high, and closing prices. The symbol is a vertical line segment, located horizontally at the x coordinate and limited vertically by the high and low prices. A horizontal tic on the left marks the opening price and one on the right marks the closing price. The length of these tics may be changed by set bar. The symbol will be unchanged if the high and low prices are interchanged. See set bar and candlesticks.


The fsteps style is only relevant to 2-d plotting. It connects consecutive points with two line segments: the first from (x1,y1) to (x1,y2) and the second from (x1,y2) to (x2,y2).


The histeps style is only relevant to 2-d plotting. It is intended for plotting histograms. Y-values are assumed to be centered at the x-values; the point at x1 is represented as a horizontal line from ((x0+x1)/2,y1) to ((x1+x2)/2,y1). The lines representing the end points are extended so that the step is centered on at x. Adjacent points are connected by a vertical line at their average x, that is, from ((x1+x2)/2,y1) to ((x1+x2)/2,y2).

If autoscale is in effect, it selects the xrange from the data rather than the steps, so the end points will appear only half as wide as the others.

histeps is only a plotting style; gnuplot does not have the ability to create bins and determine their population from some data set.


The impulses style displays a vertical line from the x axis (not the graph border), or from the grid base for splot, to each point.


The lines style connects adjacent points with straight line segments.


The linespoints style does both lines and points, that is, it draws a small symbol at each point and then connects adjacent points with straight line segments. The command set pointsize may be used to change the size of the points. See set pointsize for its usage.

linespoints may be abbreviated lp.


The points style displays a small symbol at each point. The command `set pointsize may be used to change the size of the points. See set pointsize` for its usage.


The steps style is only relevant to 2-d plotting. It connects consecutive points with two line segments: the first from (x1,y1) to (x2,y1) and the second from (x2,y1) to (x2,y2).


The vector style draws a vector from (x,y) to (x+xdelta,y+ydelta). Thus it requires four columns of data. It also draws a small arrowhead at the end of the vector.

The vector style is still experimental: it doesn't get clipped properly and other things may also be wrong with it. Use it at your own risk.


The xerrorbars style is only relevant to 2-d data plots. xerrorbars is like dots, except that a horizontal error bar is also drawn. At each point (x,y), a line is drawn from (xlow,y) to (xhigh,y) or from (x-xdelta,y) to (x+xdelta,y), depending on how many data columns are provided. A tic mark is placed at the ends of the error bar (unless set bar is used--see `set bar` for details).


The xyerrorbars style is only relevant to 2-d data plots. xyerrorbars is like dots, except that horizontal and vertical error bars are also drawn. At each point (x,y), lines are drawn from (x,y-ydelta) to (x,y+ydelta) and from (x-xdelta,y) to (x+xdelta,y) or from (x,ylow) to (x,yhigh) and from (xlow,y) to (xhigh,y), depending upon the number of data columns provided. A tic mark is placed at the ends of the error bar (unless set bar is used--see set bar for details).

If data are provided in an unsupported mixed form, the using filter on the plot command should be used to set up the appropriate form. For example, if the data are of the form (x,y,xdelta,ylow,yhigh), then you can use

     plot 'data' using 1:2:($1-$3),($1+$3),4,5 with xyerrorbars


The yerrorbars (or errorbars) style is only relevant to 2-d data plots. yerrorbars is like dots, except that a vertical error bar is also drawn. At each point (x,y), a line is drawn from (x,y-ydelta) to (x,y+ydelta) or from (x,ylow) to (x,yhigh), depending on how many data columns are provided. A tic mark is placed at the ends of the error bar (unless set bar is used--see set bar for details).

set surface

The command set surface controls the display of surfaces by splot.


     set surface
     set nosurface
     show surface

The surface is drawn with the style specifed by with, or else the appropriate style, data or function.

Whenever set nosurface is issued, splot will not draw points or lines corresponding to the function or data file points. Contours may be still be drawn on the surface, depending on the set contour option. `set nosurface; set contour base` is useful for displaying contours on the grid base. See also set contour.

set terminal

gnuplot supports many different graphics devices. Use set terminal to tell gnuplot what kind of output to generate. Use set output to redirect that output to a file or device.


     set terminal {<terminal-type>}
     show terminal

If <terminal-type> is omitted, gnuplot will list the available terminal types. <terminal-type> may be abbreviated.

If both set terminal and set output are used together, it is safest to give set terminal first, because some terminals set a flag which is needed in some operating systems.

Several terminals have additional options. For example, see dumb, iris4d, hpljii or postscript.

This document may describe drivers that are not available to you because they were not installed, or it may not describe all the drivers that are available to you, depending on its output format.

set tics

The set tics command can be used to change the tics to be drawn outwards.


     set tics {<direction>}
     show tics

where <direction> may be in (the default) or out.

See also set xtics for more control of major (labelled) tic marks and `set mxtics` for control of minor tic marks.

set ticslevel

Using splot, one can adjust the relative height of the vertical (Z) axis using set ticslevel. The numeric argument provided specifies the location of the bottom of the scale (as a fraction of the z-range) above the xy-plane. The default value is 0.5. Negative values are permitted, but tic labels on the three axes may overlap.

To place the xy-plane at a position 'pos' on the z-axis, ticslevel should be set equal to (pos - zmin) / (zmin - zmax).


     set ticslevel {<level>}
     show tics

See also set view.

set ticscale

The size of the tic marks can be adjusted with set ticscale.


     set ticscale {<major> {<minor>}}
     show tics

If <minor> is not specified, it is 0.5*<major>. The default size is 1.0 for major tics and 0.5 for minor tics. Note that it is possible to have the tic marks pointing outward by specifying a negative size.

set timestamp

The command set timestamp places the time and date of the plot in the left margin.


     set timestamp {"<format>"} {top|bottom} {{no}rotate}
                   {<xoff>}{,<yoff>} {"<font>"}
     set notimestamp
     show timestamp

The format string allows you to choose the format used to write the date and time. Its default value is what asctime() uses: "%a %b %d %H:%M:%S %Y" (weekday, month name, day of the month, hours, minutes, seconds, four-digit year). With top or bottom you can place the timestamp at the top or bottom of the left margin (default: bottom). rotate lets you write the timestamp vertically, if your terminal supports vertical text. The constants <xoff> and <off> are offsets from the default position given in character screen coordinates. <font> is used to specify the font with which the time is to be written.

The abbreviation time may be used in place of timestamp.


     set timestamp "%d/%m/%y %H:%M" 80,-2 "Helvetica"

See set timefmt for more information about time format strings.

set timefmt

This command applies to timeseries where data are composed of dates/times. It has no meaning unless the command set xdata time is given also.


     set timefmt "<format string>"
     show timefmt

The string argument tells gnuplot how to read timedata from the datafile. The valid formats are:

     Format       Explanation
     %d           day of the month, 1--31
     %m           month of the year, 1--12
     %y           year, 0--99
     %Y           year, 4-digit
     %j           day of the year, 1--365
     %H           hour, 0--24
     %M           minute, 0--60
     %S           second, 0--60
     %b           three-character abbreviation of the name of the month
     %B           name of the month

Any character is allowed in the string, but must match exactly. \t (tab) is recognized. Backslash-octals (\nnn) are converted to char. If there is no separating character between the time/date elements, then %d, %m, %y, %H, %M and %S read two digits each, %Y reads four digits and %j reads three digits. %b requires three characters, and %B requires as many as it needs.

Spaces are treated slightly differently. A space in the string stands for zero or more whitespace characters in the file. That is, "%H %M" can be used to read "1220" and "12 20" as well as "12 20".

Each set of non-blank characters in the timedata counts as one column in the using n:n specification. Thus 11:11 25/12/76 21.0 consists of three columns. To avoid confusion, gnuplot requires that you provide a complete using specification if your file contains timedata.

Since gnuplot cannot read non-numerical text, if the date format includes the day or month in words, the format string must exclude this text. But it can still be printed with the "%a", "%A", "%b", or "%B" specifier: see set format for more details about these and other options for printing timedata. (gnuplot will determine the proper month and weekday from the numerical values.)

See also set xdata and Time/date for more information.


     set timefmt "%d/%m/%Y\t%H:%M"

tells gnuplot to read date and time separated by tab. (But look closely at your data--what began as a tab may have been converted to spaces somewhere along the line; the format string must match what is actually in the file.)

set title

The set title command produces a plot title that is centered at the top of the plot. set title is a special case of set label.


     set title {"<title-text>"} {<xoff>}{,<yoff>} {"<font>,{<size>}"}
     show title

Specifying constants <xoff> or <yoff> as optional offsets for the title will move the title <xoff> or <yoff> character screen coordinates (not graph coordinates). For example, "set title ,-1" will change only the y offset of the title, moving the title down by roughly the height of one character.

<font> is used to specify the font with which the title is to be written; the units of the font <size> depend upon which terminal is used.

set title with no parameters clears the title.

See syntax for details about the processing of backslash sequences and the distinction between single- and double-quotes.

set tmargin

The command set tmargin sets the size of the top margin. Please see set margin for details.

set trange

The set trange command sets the parametric range used to compute x and y values when in parametric or polar modes. Please see set xrange for details.

set urange

The set urange and set vrange commands set the parametric ranges used to compute x, y, and z values when in splot parametric mode. Please see set xrange for details.

set variables

The show variables command lists all user-defined variables and their values.


     show variables

set version

The show version command lists the version of gnuplot being run, its last modification date, the copyright holders, and email addresses for the FAQ, the info-gnuplot mailing list, and reporting bugs--in short, the information listed on the screen when the program is invoked interactively.


     show version {long}

When the long option is given, it also lists the operating system, the compilation options used when gnuplot was installed, the location of the help file, and (again) the useful email addresses.

set view

The set view command sets the viewing angle for splots. It controls how the 3-d coordinates of the plot are mapped into the 2-d screen space. It provides controls for both rotation and scaling of the plotted data, but supports orthographic projections only.


     set view <rot_x> {,{<rot_z>}{,{<scale>}{,<scale_z>}}}
     show view

where <rot_x> and <rot_z> control the rotation angles (in degrees) in a virtual 3-d coordinate system aligned with the screen such that initially (that is, before the rotations are performed) the screen horizontal axis is x, screen vertical axis is y, and the axis perpendicular to the screen is z. The first rotation applied is <rot_x> around the x axis. The second rotation applied is <rot_z> around the new z axis.

<rot_x> is bounded to the [0:180] range with a default of 60 degrees, while <rot_z> is bounded to the [0:360] range with a default of 30 degrees. <scale> controls the scaling of the entire splot, while <scale_z> scales the z axis only. Both scales default to 1.0.


     set view 60, 30, 1, 1
     set view ,,0.5

The first sets all the four default values. The second changes only scale, to 0.5.

See also set ticslevel.

set vrange

The set urange and set vrange commands set the parametric ranges used to compute x, y, and z values when in splot parametric mode. Please see set xrange for details.

set x2data

The set x2data command sets data on the x2 (top) axis to timeseries (dates/times). Please see set xdata.

set x2dtics

The set x2dtics command changes tics on the x2 (top) axis to days of the week. Please see set xdtics for details.

set x2label

The set x2label command sets the label for the x2 (top) axis. Please see set xlabel.

set x2mtics

The set x2mtics command changes tics on the x2 (top) axis to months of the year. Please see set xmtics for details.

set x2range

The set x2range command sets the horizontal range that will be displayed on the x2 (top) axis. Please see set xrange for details.

set x2tics

The set x2tics command controls major (labelled) tics on the x2 (top) axis. Please see set xtics for details.

set x2zeroaxis

The set x2zeroaxis command draws a line at the origin of the x2 (top) axis (y2 = 0). For details, please see set zeroaxis.

set xdata

This command sets the datatype on the x axis to time/date. A similar command does the same thing for each of the other axes.


     set xdata {time}
     show xdata

The same syntax applies to ydata, zdata, x2data and y2data.

The time option signals that the datatype is indeed time/date. If the option is not specified, the datatype reverts to normal.

See set timefmt to tell gnuplot how to read date or time data. The time/date is converted to seconds from start of the century. There is currently only one timefmt, which implies that all the time/date columns must confirm to this format. Specification of ranges should be supplied as quoted strings according to this format to avoid interpretation of the time/date as an expression.

The function 'strftime' (type "man strftime" on unix to look it up) is used to print tic-mark labels. gnuplot tries to figure out a reasonable format for this unless the set format x "string" has supplied something that does not look like a decimal format (more than one '%' or neither %f nor %g).

See also Time/date for more information.

set xdtics

The set xdtics commands converts the x-axis tic marks to days of the week where 0=Sun and 6=Sat. Overflows are converted modulo 7 to dates. `set noxdtics` returns the labels to their default values. Similar commands do the same things for the other axes.


     set xdtics
     set noxdtics
     show xdtics

The same syntax applies to ydtics, zdtics, x2dtics and y2dtics.

See also the set format command.

set xlabel

The set xlabel command sets the x axis label. Similar commands set labels on the other axes.


     set xlabel {"<label>"} {<xoff>}{,<yoff>} {"<font>{,<size>}"}
     show xlabel

The same syntax applies to x2label, ylabel, y2label and zlabel.

Specifying the constants <xoff> or <yoff> as optional offsets for a label will move it <xoff> or <yoff> character widths or heights. For example, " set xlabel -1" will change only the x offset of the xlabel, moving the label roughly one character width to the left. The size of a character depends on both the font and the terminal.

<font> is used to specify the font in which the label is written; the units of the font <size> depend upon which terminal is used.

To clear a label, put no options on the command line, e.g., "set y2label".

The default positions of the axis labels are as follows:

xlabel: The x-axis label is centered below the bottom axis.

ylabel: The position of the y-axis label depends on the terminal, and can be one of the following three positions:

1. Horizontal text flushed left at the top left of the plot. Terminals that cannot rotate text will probably use this method. If set x2tics is also in use, the ylabel may overwrite the left-most x2tic label. This may be remedied by adjusting the ylabel position or the left margin.

2. Vertical text centered vertically at the left of the plot. Terminals that can rotate text will probably use this method.

3. Horizontal text centered vertically at the left of the plot. The EEPIC, LaTeX and TPIC drivers use this method. The user must insert line breaks using \\ to prevent the ylabel from overwriting the plot. To produce a vertical row of characters, add \\ between every printing character (but this is ugly).

zlabel: The z-axis label is centered along the z axis and placed in the space above the grid level.

y2label: The y2-axis label is placed to the right of the y2 axis. The position is terminal-dependent in the same manner as is the y-axis label.

x2label: The x2-axis label is placed above the top axis but below the plot title. It is also possible to create an x2-axis label by using new-line characters to make a multi-line plot title, e.g.,

     set title "This is the title\n\nThis is the x2label"

Note that double quotes must be used. The same font will be used for both lines, of course.

If you are not satisfied with the default position of an axis label, use `set label` instead--that command gives you much more control over where text is placed.

Please see set syntax for further information about backslash processing and the difference between single- and double-quoted strings.

set xmtics

The set xmtics commands converts the x-axis tic marks to months of the year where 1=Jan and 12=Dec. Overflows are converted modulo 12 to months. The tics are returned to their default labels by set noxmtics. Similar commands perform the same duties for the other axes.


     set xmtics
     set noxmtics
     show xmtics

The same syntax applies to x2mtics, ymtics, y2mtics, and zmtics.

See also the set format command.

set xrange

The set xrange command sets the horizontal range that will be displayed. A similar command exists for each of the other axes, as well as for the polar radius r and the parametric variables t, u, and v.


     set xrange [{{<min>}:{<max>}}] {{no}reverse} {{no}writeback}
     show xrange

where <min> and <max> terms are constants, expressions or an asterisk to set autoscaling. If the data are time/date, you must give the range as a quoted string according to the set timefmt format. Any value omitted will not be changed.

The same syntax applies to yrange, zrange, x2range, y2range, rrange, trange, urange and vrange.

The reverse option reverses the direction of the axis, e.g., `set xrange [0:1] reverse` will produce an axis with 1 on the left and 0 on the right. This is identical to the axis produced by set xrange [1:0], of course. reverse is intended primarily for use with autoscale.

The writeback option essentially saves the range found by autoscale in the buffers that would be filled by set xrange. This is useful if you wish to plot several functions together but have the range determined by only some of them. The writeback operation is performed during the plot execution, so it must be specified before that command. For example,

     set xrange [-10:10]
     set yrange [] writeback
     plot sin(x)
     set noautoscale y
     replot x/2

results in a yrange of [-1:1] as found only from the range of sin(x); the [-5:5] range of x/2 is ignored. Executing show yrange after each command in the above example should help you understand what is going on.

In 2-d, xrange and yrange determine the extent of the axes, trange determines the range of the parametric variable in parametric mode or the range of the angle in polar mode. Similarly in parametric 3-d, xrange, yrange, and zrange govern the axes and urange and vrange govern the parametric variables.

In polar mode, rrange determines the radial range plotted. <rmin> acts as an additive constant to the radius, whereas <rmax> acts as a clip to the radius--no point with radius greater than <rmax> will be plotted. xrange and yrange are affected--the ranges can be set as if the graph was of r(t)-rmin, with rmin added to all the labels.

Any range may be partially or totally autoscaled, although it may not make sense to autoscale a parametric variable unless it is plotted with data.

Ranges may also be specified on the plot command line. A range given on the plot line will be used for that single plot command; a range given by a set command will be used for all subsequent plots that do not specify their own ranges. The same holds true for splot.


To set the xrange to the default:

     set xrange [-10:10]

To set the yrange to increase downwards:

     set yrange [10:-10]

To change zmax to 10 without affecting zmin (which may still be autoscaled):

     set zrange [:10]

To autoscale xmin while leaving xmax unchanged:

     set xrange [*:]

set xtics

Fine control of the major (labelled) tics on the x axis is possible with the set xtics command. The tics may be turned off with the set noxtics command, and may be turned on (the default state) with set xtics. Similar commands control the major tics on the y, z, x2 and y2 axes.


     set xtics {axis | border} {{no}mirror} {{no}rotate}
               {  autofreq
                | <incr>
                | <start>, <incr> {,<end>}
                | ({"<label>"} <pos> {,{"<label>"} <pos>}...) }
     set noxtics
     show xtics

The same syntax applies to ytics, ztics, x2tics and y2tics.

axis or border tells gnuplot to put the tics (both the tics themselves and the accompanying labels) along the axis or the border, respectively. mirror tells it to put unlabelled tics at the same positions on the opposite border. nomirror does what you think it does. rotate asks gnuplot to rotate the text through 90 degrees, if the underlying terminal driver supports text rotation. norotate cancels this. The defaults are border mirror norotate for tics on the x and y axes, and `border nomirror norotate for tics on the x2 and y2 axes. For the z axis, the the {axis | border} option is not available and the default is nomirror`. If you do want to mirror the z-axis tics, you might want to create a bit more room for them with set border.

set xtics with no options restores the default border if xtics are not being displayed; otherwise it has no effect. Any previously specified tic frequency or position {and labels} are retained.

Positions of the tics are calculated automatically by default or if the autofreq option is given; otherwise they may be specified in either of two forms:

The implicit <start>, <incr>, <end> form specifies that a series of tics will be plotted on the axis between the values <start> and <end> with an increment of <incr>. If <end> is not given, it is assumed to be infinity. The increment may be negative. If neither <start> nor <end> is given, <start> is assumed to be negative infinity, <end> is assumed to be positive infinity, and the tics will be drawn at integral multiples of <step>. If the axis is logarithmic, the increment will be used as a multiplicative factor.


Make tics at 0, 0.5, 1, 1.5, ..., 9.5, 10.

     set xtics 0,.5,10

Make tics at ..., -10, -5, 0, 5, 10, ...

     set xtics 5

Make tics at 1, 100, 1e4, 1e6, 1e8.

     set logscale x; set xtics 1,100,10e8

The explicit ("<label>" <pos>, ...) form allows arbitrary tic positions or non-numeric tic labels. A set of tics is a set of positions, each with its own optional label. Note that the label is a string enclosed by quotes. It may be a constant string, such as "hello", may contain formatting information for converting the position into its label, such as "%3f clients", or may be empty, "". See set format for more information. If no string is given, the default label (numerical) is used. In this form, the tics do not need to be listed in numerical order.


     set xtics ("low" 0, "medium" 50, "high" 100)
     set xtics (1,2,4,8,16,32,64,128,256,512,1024)
     set ytics ("bottom" 0, "" 10, "top" 20)

In the second example, all tics are labelled. In the third, only the end tics are labelled.

However they are specified, tics will only be plotted when in range.

Format (or omission) of the tic labels is controlled by set format, unless the explicit text of a labels is included in the set xtic (<label>) form.

Minor (unlabelled) tics can be added by the set mxtics command.

In case of timeseries data, position values must be given as quoted dates or times according to the format timefmt. If the <start>, <incr>, <end> form is used, <start> and <end> must be given according to timefmt, but <incr> must be in seconds. Times will be written out according to the format given on set format, however.


     set xdata time
     set timefmt "%d/%m"
     set format x "%b %d"
     set xrange ["01/12":"06/12"]
     set xtics "01/12", 172800, "05/12"
     set xdata time
     set timefmt "%d/%m"
     set format x "%b %d"
     set xrange ["01/12":"06/12"]
     set xtics ("01/12", "" "03/12", "05/12")

Both of these will produce tics "Dec 1", "Dec 3", and "Dec 5", but in the second example the tic at "Dec 3" will be unlabelled.

set xzeroaxis

The set xzeroaxis command draws a line at y = 0. For details, please see set zeroaxis.

set y2data

The set y2data command sets y2 (right-hand) axis data to timeseries (dates/times). Please see set xdata.

set y2dtics

The set y2dtics command changes tics on the y2 (right-hand) axis to days of the week. Please see set xdtics for details.

set y2label

The set y2dtics command sets the label for the y2 (right-hand) axis. Please see set xlabel.

set y2mtics

The set y2mtics command changes tics on the y2 (right-hand) axis to months of the year. Please see set xmtics for details.

set y2range

The set y2range command sets the vertical range that will be displayed on the y2 (right-hand) axis. Please see set xrange for details.

set y2tics

The set y2tics command controls major (labelled) tics on the y2 (right-hand) axis. Please see set xtics for details.

set y2zeroaxis

The set y2zeroaxis command draws a line at the origin of the y2 (right-hand) axis (x2 = 0). For details, please see set zeroaxis.

set ydata

Sets y-axis data to timeseries (dates/times). Please see set xdata.

set ydtics

The set ydtics command changes tics on the y axis to days of the week. Please see set xdtics for details.

set ylabel

This command sets the label for the y axis. Please see set xlabel.

set ymtics

The set ymtics command changes tics on the y axis to months of the year. Please see set xmtics for details.

set yrange

The set yrange command sets the vertical range that will be displayed on the y axis. Please see set xrange for details.

set ytics

The set ytics command controls major (labelled) tics on the y axis. Please see set xtics for details.

set yzeroaxis

The set yzeroaxis command draws a line at x = 0. For details, please see set zeroaxis.

set zdata

Set zaxis date to timeseries (dates/times). Please see set xdata.

set zdtics

The set zdtics command changes tics on the z axis to days of the week. Please see set xdtics for details.

set zero

The zero value is the default threshold for values approaching 0.0.


     set zero <expression>
     show zero

gnuplot will not plot a point if its imaginary part is greater in magnitude than the zero threshold. This threshold is also used in various other parts of gnuplot as a (crude) numerical-error threshold. The default zero value is 1e-8. zero values larger than 1e-3 (the reciprocal of the number of pixels in a typical bitmap display) should probably be avoided, but it is not unreasonable to set zero to 0.0.

set zeroaxis

The x axis may be drawn by set xzeroaxis and removed by set noxzeroaxis. Similar commands behave similarly for the y, x2, and y2 axes.


     set {x|x2|y|y2|}zeroaxis { {linestyle | ls <line_style>}
                                | { linetype | lt <line_type>}
                                  { linewidth | lw <line_width>}}
     set no{x|x2|y|y2|}zeroaxis
     show {x|y|}zeroaxis

By default, these options are off. The selected zero axis is drawn with a line of type <line_type> and width <line_width> (if supported by the terminal driver currently in use), or a user-defined style <line_style>.

If no linetype is specified, any zero axes selected will be drawn using the axis linetype (linetype 0).

set zeroaxis l is equivalent to set xzeroaxis l; set yzeroaxis l. `set nozeroaxis is equivalent to set noxzeroaxis; set noyzeroaxis`.

set zlabel

This command sets the label for the z axis. Please see set xlabel.

set zmtics

The set zmtics command changes tics on the z axis to months of the year. Please see set xmtics for details.

set zrange

The set zrange command sets the range that will be displayed on the z axis. The zrange is used only by splot and is ignored by plot. Please see `set xrange` for details.

set ztics

The set ztics command controls major (labelled) tics on the z axis. Please see set xtics for details.

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