[Gnuplot-info] KeyForSplotContoursFromMatrix

[Geoff K. <ge...@ka...>]

My code for setting up a contour plot of matrix data is:

reset session
set datafile missing "?.????"
set xtics ...; set ytics ...

set zrange [-1.:1.0] set ztics -1.0, 0.1, 1.0 format "%3.1f";

unset key;
ltitle = "   {/Symbol l}_{xy}"
set key outside title ltitle offset -4.0, -0.2

set view map; set contour; set xyplane 0.0
set grid; set cntrparam levels 20; set isosamples 150

splot [X_min:X_max][Y_min:Y_max] 'matrixdata' nonuniform matrix 
nosurface title " " w linesp

All works as expected apart from the key:

1. The format of the z values is d.d, apart from z=0.0: displayed as "0"
How do I format the z values in the key?

2. The plot shows the contour lines with data point symbols. These are 
missing from the key.
Can splot show the data point symbols, or do I have to create my own key 
using set object?

You can view the plot image at www.kaniuk.co.uk/gptest/splot-contour.eps
If you need to see the exact .gp script I can provide that.

Your help is much appreciated!

Geoff