Bars

Bmargin

The command set bmargin sets the size of the bottom margin. Please see set margin (p. 125) for details.

Border

The set border and unset border commands control the display of the graph borders for the plot and splot commands. Note that the borders do not necessarily coincide with the axes; with plot they often do, but with splot they usually do not.

Syntax:

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

unset border show border

With a splot displayed in an arbitrary orientation, like set view 56,103, the four corners of the x-y plane can be referred to as "front", "back", "left" and "right". A similar set of four corners exist for the top surface, of course. Thus the border connecting, say, the back and right corners of the x-y plane is the "bottom right back" border, and the border connecting the top and bottom front corners is the "front vertical". (This nomenclature is de ned solely to allow the reader to gure out the table that follows.)

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, <integer> should be the sum of the appropriate entries from the following table:

Graph Border Encoding

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

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

In 2D plots the border is normally drawn on top of all plots elements (front). If you want the border to be drawn behind the plot elements, use set border back.

Using the optional <line style>, <line type> and <line width> speci ers, the way the border lines are drawn can be in uenced (limited by what the current terminal driver supports).

For plot, tics may be drawn on edges other than bottom and left by enabling the second axes { see set xtics (p. 160) for details.

If a splot draws only on the base, as is the case with "unset surface; set contour base", then the verticals and the top are not drawn even if they are speci ed.

The set grid options 'back', 'front' and 'layerdefault' also control the order in which the border lines are drawn with respect to the output of the plotted data.

Examples:

Draw default borders:

set border

Draw only the left and bottom (plot) or both front and back bottom left (splot) borders: set border 3

Draw a complete box around a splot: set border 4095

Draw a topless box around a splot, omitting the front vertical: set border 127+256+512 # or set border 1023-128

Draw only the top and right borders for a plot and label them as axes:

unset xtics; unset ytics; set x2tics; set y2tics; set border 12

Boxwidth

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

Syntax:

set boxwidth {<width>} {absolute|relative} show boxwidth

By default, adjacent boxes are extended in width until they touch each other. A di erent default width may be speci ed using the set boxwidth command. Relative widths are interpreted as being a fraction of this default width.

An explicit value for the boxwidth is interpreted as being a number of units along the current x axis (absolute) unless the modi er relative is given. If the x axis is a log-scale (see set log (p. 124)) then the value of boxwidth is truly "absolute" only at x=1; this physical width is maintained everywhere along the axis (i.e. the boxes do not become narrower the value of x increases). If the range spanned by a log scale x axis is far from x=1, some experimentation may be required to nd a useful value of boxwidth.

The default is superseded by explicit width information taken from an extra data column in styles boxes or boxerrorbars. 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 style boxes (p. 43) and style boxerrorbars (p. 43) 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 e ect can be achieved with the using keyword in plot: plot 'file' using 1:2:3:4:(-2)

To set the box width to half of the automatic size use set boxwidth 0.5 relative

To set the box width to an absolute value of 2 use set boxwidth 2 absolute

Clabel

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

Syntax:

102 gnuplot 4.6

set clabel {'<format>'} unset clabel

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 con guration.

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

See also set contour (p. 105).

Clip

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

set clip <clip-type> unset clip <clip-type> show clip

Three clip types for points and lines are supported by gnuplot: points, one, and two. One, two, or all three clip types may be active for a single graph. Note that clipping of color lled quadrangles drawn by pm3d maps and surfaces is not controlled by this command, but by set pm3d clip1in and set pm3d clip4in.

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 unset clip

set clip is synonymous with set clip points; unset clip turns o all three types of clipping.

Cntrparam

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

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.

For auto, <n> speci es 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 speci ed; the number of discrete levels sets the number of contour levels. In discrete mode, any set cntrparam 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 z axis is logarithmic, <increment> will be interpreted as a factor, just like in set ztics.

If the command set cntrparam is given without any arguments speci ed, 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: