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.
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.
Syntax:
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.
x={1.0,0.1}
set angles radians
y=sinh(x)
print y #prints {1.16933, 0.154051}
print asinh(y) #prints {1.0, 0.1}
but
set angles degrees
y=sinh(x)
print y #prints {1.16933, 0.154051}
print asinh(y) #prints {57.29578, 5.729578}
Arbitrary arrows can be placed on a plot using the set arrow command.
Syntax:
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.
Examples:
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
Autoscaling may be set individually on the x, y or z axis or globally on all axes. The default is to autoscale all axes.
Syntax:
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.
Examples:
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
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.
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.
The set bar command controls the tics at the ends of errorbars.
Syntax:
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.
The command set bmargin sets the size of the bottom margin. Please see
set margin for details.
The set border and set noborder commands control the display of the graph
borders for the plot and splot commands.
Syntax:
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.
Examples:
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
The set boxwidth command is used to set the default width of boxes in the
boxes and boxerrorbars styles.
Syntax:
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)
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.
Syntax:
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.
gnuplot can clip data points and lines that are near the boundaries of a
graph.
Syntax:
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 controls the generation of contours and their smoothness for
a contour plot. show contour displays current settings of cntrparam as
well as contour.
Syntax:
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.
Examples:
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 enables contour drawing for surfaces. This option is available
for splot only.
Syntax:
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.
The set data style command changes the default plotting style for data
plots.
Syntax:
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.
The set dgrid3d command enables, and can set parameters for, non-grid
to grid data mapping.
Syntax:
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.)
Examples:
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.
The set dummy command changes the default dummy variable names.
Syntax:
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.
Examples:
set dummy u,v
set dummy ,s
The second example sets the second variable to s.
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.
Syntax:
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.
The format of the tic-mark labels can be set with the set format command.
Syntax:
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.
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.
Examples:
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.
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.
Examples:
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"
The set function style command changes the default plotting style for
function plots.
Syntax:
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.
The show functions command lists all user-defined functions and their
definitions.
Syntax:
show functions
For information about the definition and usage of functions in gnuplot,
please see expressions.
The set grid command allows grid lines to be drawn on the plot.
Syntax:
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.
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.
Syntax:
set hidden3d {defaults} |
{ {{offset <offset>} | {nooffset}}
{trianglepattern <bitpattern>}
{{undefined <level>} | {noundefined}}
{{no}altdiagonal}
{{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:
C----B
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.
The isoline density (grid) for plotting functions as surfaces may be changed
by the set isosamples command.
Syntax:
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.
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.
Syntax:
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.
Examples:
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
Arbitrary labels can be placed on the plot using the set label command.
Syntax:
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.
Examples:
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
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.
Syntax:
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.
The command set lmargin sets the size of the left margin. Please see
set margin for details.
The locale setting determines the language with which {x,y,z}{d,m}tics
will write the days and months.
Syntax:
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.
Log scaling may be set on the x, y, z, x2 and/or y2 axes.
Syntax:
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.
Examples:
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
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.
Syntax:
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.
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.
Syntax:
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.
The set missing command allows you to tell gnuplot what character is
used in a data file to denote missing data.
Syntax:
set missing {"<character>"}
show missing
Example:
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.
The command set multiplot places gnuplot in the multiplot mode, in which
several plots are placed on the same page, window, or screen.
Syntax:
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.
Example:
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.
Minor tic marks along the x2 (top) axis are controlled by set mx2tics.
Please see 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.
Syntax:
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.
Minor tic marks along the y2 (right-hand) axis are controlled by `set
my2tics. Please see set mxtics`.
Minor tic marks along the y axis are controlled by set mytics. Please
see set mxtics.
Minor tic marks along the z axis are controlled by set mztics. Please
see set mxtics.
Offsets provide a mechanism to put a boundary around the data inside of an autoscaled graph.
Syntax:
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.
Example:
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.
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).
Syntax:
set origin <x-origin>,<y-origin>
By default, screens are displayed to the standard output. The set output
command redirects the display to the specified file or device.
Syntax:
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.
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.
Syntax:
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.
The set pointsize command scales the size of the points used in plots.
Syntax:
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.
The set polar command changes the meaning of the plot from rectangular
coordinates to polar coordinates.
Syntax:
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.
Example:
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.
The command set rmargin sets the size of the right margin. Please see
set margin for details.
The set rrange command sets the range of the radial coordinate for a
graph in polar mode. Please see set xrange for details.
The sampling rate of functions, or for interpolating data, may be changed
by the set samples command.
Syntax:
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`.
The set size command scales the displayed size of the plot.
Syntax:
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.
Examples:
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
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.
Syntax:
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).
The command set surface controls the display of surfaces by splot.
Syntax:
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.
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.
Syntax:
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.
The set tics command can be used to change the tics to be drawn outwards.
Syntax:
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.
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).
Syntax:
set ticslevel {<level>}
show tics
See also set view.
The size of the tic marks can be adjusted with set ticscale.
Syntax:
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.
The command set timestamp places the time and date of the plot in the left
margin.
Syntax:
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.
Example:
set timestamp "%d/%m/%y %H:%M" 80,-2 "Helvetica"
See set timefmt for more information about time format strings.
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.
Syntax:
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.
Example:
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.)
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.
Syntax:
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.
The command set tmargin sets the size of the top margin. Please see
set margin for details.
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.
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.
The show variables command lists all user-defined variables and their
values.
Syntax:
show variables
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.
Syntax:
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.
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.
Syntax:
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.
Examples:
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.
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.
The set x2data command sets data on the x2 (top) axis to timeseries
(dates/times). Please see set xdata.
The set x2dtics command changes tics on the x2 (top) axis to days of the
week. Please see set xdtics for details.
The set x2label command sets the label for the x2 (top) axis. Please see
set xlabel.
The set x2mtics command changes tics on the x2 (top) axis to months of the
year. Please see set xmtics for details.
The set x2range command sets the horizontal range that will be displayed on
the x2 (top) axis. Please see set xrange for details.
The set x2tics command controls major (labelled) tics on the x2 (top) axis.
Please see set xtics for details.
The set x2zeroaxis command draws a line at the origin of the x2 (top) axis
(y2 = 0). For details, please see
set zeroaxis.
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.
Syntax:
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.
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.
Syntax:
set xdtics
set noxdtics
show xdtics
The same syntax applies to ydtics, zdtics, x2dtics and y2dtics.
See also the set format command.
The set xlabel command sets the x axis label. Similar commands set labels
on the other axes.
Syntax:
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.
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.
Syntax:
set xmtics
set noxmtics
show xmtics
The same syntax applies to x2mtics, ymtics, y2mtics, and zmtics.
See also the set format command.
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.
Syntax:
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.
Examples:
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 [*:]
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.
Syntax:
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.
Examples:
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.
Examples:
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.
Examples:
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.
The set xzeroaxis command draws a line at y = 0. For details, please see
set zeroaxis.
The set y2data command sets y2 (right-hand) axis data to timeseries
(dates/times). Please see set xdata.
The set y2dtics command changes tics on the y2 (right-hand) axis to days of
the week. Please see set xdtics for details.
The set y2dtics command sets the label for the y2 (right-hand) axis.
Please see set xlabel.
The set y2mtics command changes tics on the y2 (right-hand) axis to months
of the year. Please see set xmtics for details.
The set y2range command sets the vertical range that will be displayed on
the y2 (right-hand) axis. Please see set xrange for details.
The set y2tics command controls major (labelled) tics on the y2 (right-hand)
axis. Please see set xtics for details.
The set y2zeroaxis command draws a line at the origin of the y2 (right-hand)
axis (x2 = 0). For details, please see set zeroaxis.
Sets y-axis data to timeseries (dates/times). Please see set xdata.
The set ydtics command changes tics on the y axis to days of the week.
Please see set xdtics for details.
This command sets the label for the y axis. Please see set xlabel.
The set ymtics command changes tics on the y axis to months of the year.
Please see set xmtics for details.
The set yrange command sets the vertical range that will be displayed on
the y axis. Please see set xrange for details.
The set ytics command controls major (labelled) tics on the y axis.
Please see set xtics for details.
The set yzeroaxis command draws a line at x = 0. For details, please see
set zeroaxis.
Set zaxis date to timeseries (dates/times). Please see set xdata.
The set zdtics command changes tics on the z axis to days of the week.
Please see set xdtics for details.
The zero value is the default threshold for values approaching 0.0.
Syntax:
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.
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.
Syntax:
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`.
This command sets the label for the z axis. Please see set xlabel.
The set zmtics command changes tics on the z axis to months of the year.
Please see set xmtics for details.
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.
The set ztics command controls major (labelled) tics on the z axis.
Please see set xtics for details.