Should 'splot' and 'plot' treat NaN data differently?

[Dima K. <gn...@di...>]

Hi.

I'm plotting some binary data 'with image' (using the most recent
gnuplot in the repo). The data has a few NaN and a few Inf values in it.
I'm seeing that these points are rendered differently between
otherwise-identical 'plot' and 'splot' plots.

I'm attaching a sample data file that has some NaNs. The command I'm
using to plot is

 set view map
 splot '/tmp/inconsistent_nan.dat' binary array=(155,5) format="%float" with image

The 'plot' command is identical except using 'plot' instead of 'splot'.

At full zoom-out, the 'splot' draws NaN in white, -inf in black and +inf
in yellow. The colors autoscale, so these mappings were done by drawing
-inf with the lowest-range color, +inf with the highest-range color, and
nan as transparent.

The 'splot' version just sets the infs and the nans to 0. This lies in
the middle of the range for this dataset, so the rendering is roughly
red.

I'm not against either of these behaviors, but I think them being
different is a bug. Thoughts?

dima