GNUPlot Manual

36 SET-SHOW gnuplot 4.0 69
36.24 Grid
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}
{{no}{m}cbtics}
{polar {}}
{layerdefault | front | back}
{ {linestyle }
| {linetype | lt }
{linewidth | lw }
{ , {linestyle | ls }
| {linetype | lt }
{linewidth | lw } } }
unset grid
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.
If front is given, the grid is drawn on top of the graphed data. If back is given, the grid is drawn
underneath the graphed data. Using front will prevent the grid from being obscured by dense data.
The default setup, layerdefault, is equivalent to back for 2d plots. In 3D plots the default is to split
up the grid and the graph box into two layers: one behind, the other in front of the plotted data and
functions. Since hidden3d mode does its own sorting, it ignores all grid drawing order options and
passes the grid lines through the hidden line removal machinery instead. These options actually affect
not only the grid, but also the lines output by set border and the various ticmarks (see set xtics
(p. 149)).
Z grid lines are drawn on the bottom of the plot. This looks better if a partial box is drawn around the
plot — see set border (p. 56).
36.25 Hidden3d
The set hidden3d command enables hidden line removal for surface plotting (see splot (p. 154)).
Some optional features of the underlying algorithm can also be controlled using this command.
Syntax:
set hidden3d {defaults} |
{ {{offset } | {nooffset}}
{trianglepattern }
{{undefined } | {noundefined}}
{{no}altdiagonal}
{{no}bentover} }
unset hidden3d
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.