Re: Strangeness with PM3D

[Petr M. <mi...@ph...>]

> In trying to figure out why some of the output files produced by the
> canvas driver are so large, I stumbled across a strange pm3d problem
> that seems to affect many drivers.  It shows up in several of the demos,
> but the most extreme case is transparent_solids.dem.
> 
> The issue is this line in pm3d.c
>   693:         /* set the color */
>   694:         set_color(gray);
> 
> The line is clearly necessary in the general case, but there must be one
> or more conditions in which the loop containing this line is executed
> many times even though no pm3d quadrangles are actually drawn.
> This results in huge numbers of useless color setting commands in the
> output file.  For instance, if you run it through the postscript driver
>    set term post color solid
>    set output 'ts.ps'
>    load 'transparent_solids.dem'
> 
> you will find in the output file lines like the following:
> %pm3d_map_begin
> .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4729 g .4218 g .4218 g .4218 g .4218 g .4218 g .4218 g .4218 g .4218 g .4218 g .4218 g .4218 g .4218 g .4218 g .4218 g .4218 g .4218 g .4218 g .4218 g .4218 g .4218 g .4218 g .4218 g .4218 g .4218 g .4218 g .4218 g .4218 g .4218 g .4218 g .4218 g .4218 g .4218 g .4218 g .4218 g .4218 g .4218 g .4218 g .4218 g .4218 g .4218 g .4218 g .4218 g .4218 g .4218 g .4218 g .4218 g .4218 g .4218 g .4218 g .4218 g .4218 g .4218 g .4218 g .4218 g .4218 g .4218 g .4218 g .4218 g .4218 g .4218 g  ... [snip] %pm3d_map_end
>
> How can we get rid of this unwanted output?

It was a problem of the depthorder option, here is the shortest test case:

set pm3d depthorder
splot x*x+y*y with pm3d
set term post color; set out 'z.ps'
replot
set out; set term pop


I have fixed it.

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PM