Re: segfault in plot3d

[Daniel J S. <dan...@ie...>]

James R. Van Zandt wrote:

> Daniel J Sebald <dan...@ie...> wrote:
> 
>>That explains it.  The double line break means to start another 3D
>>curve.  (A single break means to start another trace of the 3D curve.)
>>So Jim's example is attempting a 3D plot with single dimensioned data.
> 
> 
> I don't follow what you mean by "single dimensioned data".  Each point
> has an X, Y, and Z value.  With "set style data lines", the points are
> connected along only one dimension, which is fine with me.  Actually I
> was using the default style, so I got only the points.
> 
> 
>>Either a check should be put in plot3d.c, or a datafile [like this]
>>should be disallowed...
> 
> 
> I see no reason to disallow it.  It used to work.  And it still works
> unless you plot data after a function.  (Succeeds by accident?)

Good chance, would be my guess.  Someone disallowed the number of samples in a dimension to be 1.


> The docs say
> 
> "If all datablocks contain the same number of points, gnuplot will
> draw cross-isolines between datablocks, connecting corresponding
> points."
> 
> Apparently gnuplot should check that there is more than one datablock
> before attempting to draw cross-isolines.

Yes.

Philosophically, I'm not opposed to having a single line of data appear in a 3D plot.  It's probably the case that 3D plotting functions expect (i.e., assume, or, were never tested) there to be some type of grid.

Dan