gnuplot documentation

106 gnuplot 4.3 70 SET-SHOW
set isosamples {,}
show isosamples
Each function surface plot will have iso-u lines and iso-v lines. If you only specify
, will be set to the same value as . 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 (p. 129) and set hidden3d
(p. 104). 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.
70.28 Key
The set key command 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 (p. 79) and plot with (p. 79) for more information.
Syntax:
set key {on|off} {default}
{{inside | outside} | {lmargin | rmargin | tmargin | bmargin}
| {at }}
{left | right | center} {top | bottom | center}
{vertical | horizontal} {Left | Right}
{{no}reverse} {{no}invert}
{samplen } {spacing }
{width }
{height }
{{no}autotitle {columnheader}}
{title ""} {{no}enhanced}
{font ","} {textcolor }
{{no}box { {linestyle | ls }
| {linetype | lt }
{linewidth | lw }}}
unset key
show key
The key contains a title and a sample (line, point, box) for each plot in the graph. The key may be
turned off by requesting set key off or unset key. Individual key entries may be turned off by using
the notitle keyword in the corresponding plot command.
Elements within the key are stacked according to vertical or horizontal. In the case of vertical, the
key occupies as few columns as possible. That is, elements are aligned in a column until running out of
vertical space at which point a new column is started. In the case of horizontal, the key occupies as
few rows as possible.
By default the key is placed in the upper right inside corner of the graph. The keywords left, right,
top, bottom, center, inside, outside, lmargin, rmargin, tmargin, bmargin (, above, over,
below and under) may be used to automatically place the key in other positions of the graph. Also an
at may be given to indicate precisely where the plot should be placed. In this case, the
keywords left, right, top, bottom and center serve an analogous purpose for alignment. For more
information, see key placement (p. 108).