Second attempt at a response. Just forget about anything I said the first time around. I never use in-line ranges myself, so I always get confused when I see them as to exactly what they apply to. Unfortunately this confusion may extend to what the program thinks it means and what the user thinks it means. There are several issues here. It looks like you expecting the program to figure out that it should generate appropriate samples spanning the range of '+'. This doesn't happen for your minimal...
Second attempt at a response. Just forget about anything I said the first time around. I never use in-line ranges myself, so I always get confused when I see them as to exactly what they apply to. Unfortunately this confusion may extend to what the program thinks it means and what the user thinks it means. There are several issues here. It looks like you expecting the program to figure out that it should generate appropriate samples spanning the range of '+'. This doesn't happen for your minimal...
[6.0.0] `fit` finicky about the range
unchangeable sample size of 10 on y axis in pm3d map
[6.0.0] `fit` finicky about the range
The sampling intervals along x are controlled by set samples; the intervals along y are controlled by set isosamples. I do not know why the name "isosamples" was chosen. set pm3d map border lt black set samples 50 set isosamples 50 splot x*x + y*y
The sampling intervals along x are controlled by set samples; the intervals along y are controlled by set isosamples. I do not know why the name "isosamples" was chosen. set pm3d map border lt black set samples 50 set isosamples 50 splot x*x + y*y
qtterm: input lines ignored after the plot window is closed