Issues in gnuplot: pm3d and dgrid3d

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The discussion centers on using gnuplot to visualize 3D coordinate data generated from a Fortran program. Initially, the user encountered issues with the pm3d and dgrid3d functions, resulting in a "sliced" surface that did not appear smooth or continuous, despite attempts to increase grid resolution. The user later resolved the issue by scaling down the x-values in the data, which led to the desired smooth surface. This raises questions about potential bugs in the pm3d function within gnuplot, as the problem seemed to stem from the original data scale. The user hopes their solution will assist others facing similar challenges.
abonatto
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Dear All,

I am using gnuplot to make plots from data files generated using a fortran program. Those data files are basically big lists of 3d coordinates, just like like (not my real data, just an example):

10.0 1.00 0.01
20.0 1.00 0.14
...

So, when I use splot, I generate plot 1 (attached), and it is ok. But, after that, when I use pm3d ("set pm3d") and dgrid3d ("set dgrid3d 64,64,1", for example), it plots plot 2 (attached), which is pretty different from B]plot 1[/B]: the surface generated is "sliced", and it is not a continuous and smooth surface that it should be.

I have tried to plot with higher values in dgrid3d (256,256,3 and others...), but the problem still happens).

I really would appreciate any help on this :-)

Alexandre
 

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Dear All,

Its me again! I have "solved" the problem, and I will post here what I did (I hope it helps someone someday :)

All I did was to divide the x-values (0 to 2.5e+06; look in plot 2 attached in the previous post) for 1e+06 (in gnuplot I changed column 1 for "($1/1000000)": please see in plot 3, attached in this post, that x-values now are between 0 and 2.5). Now I got a continuous and smooth surface, just as I was expecting to see (based on plot 1 grid of points). Would this be a bug with pm3d function in gnuplot?

Thanks to everybody who read this post!
 

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