GNUPlot Manual

60 gnuplot 4.0 36 SET-SHOW
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 (p. 61) for control of where the contours are drawn, and set clabel (p. 58) for
control of the format of the contour labels and linetypes.
See also
and
contours demo (contours.dem)
contours with user defined levels demo (discrete.dem).
36.11 Color box
The color scheme, i.e. the gradient of the smooth color with min z and max z values of pm3d’s palette,
is drawn in a color box unless unset colorbox.
set colorbox
set colorbox {
{ vertical | horizontal }
{ default | user }
{ origin x, y }
{ size x, y }
{ noborder | bdefault | border [line style] }
}
show colorbox
unset colorbox
Colorbox position can be default or user. If the latter is specified the values as given with the origin
and size subcommands are used.
vertical and horizontal switches the orientation of the color gradient.
origin x, y and size x, y are used only in combination with the user option. The x and y values must
be given in screen coordinates (as everything else did not seem to make sense) that is between [0 - 1].
Try for example:
set colorbox horiz user origin .1,.02 size .8,.04
which will draw a horizontal gradient somewhere at the bottom of the graph.
border turns the border on (this is the default). noborder turns the border off. If an positive integer
argument is given after border, it is used as a line style tag which is used for drawing the border, e.g.:
set style line 2604 linetype -1 linewidth .4
set colorbox border 2604
will use line style 2604, a thin line with the default border color (-1) for drawing the border. bdefault
(which is the default) will use the default border line style for drawing the border of the color box.
The axis of the color box is called cb and it is controlled by means of the usual axes commands,
i.e. set/unset/show with cbrange, [m]cbtics, format cb, grid [m]cb, cblabel, and perhaps even
cbdata, [no]cbdtics, [no]cbmtics.
set colorbox without any parameter switches the position to default.
default parameters for the colorbox and switches the colorbox off.
unset colorbox resets the
See also help for set pm3d (p. 82), set palette (p. 85), x11 pm3d (p. 141), and set style line
(p. 94).