non rectangular density plots

Question

pfb 2011-8-4

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/13067-non-rectangular-density-plots

Hi all,

I have to produce density plots like those obtained e.g. with imagesc, but on a triangular domain. That is: the "pixels" of my image lay on a triangular instead of a rectangular lattice. Of course I could use imagesc, filling only one half of a rectangular lattice (matrix), but this choice is not as aesthetically appealing and hides the symmetry of the problem. I get a rectangular triangle instead of an equilateral one.

What I'm doing now is plotting '.' markers at the sites of the triangular lattice, and then adding custom-made axes. The result is sort of ok, but I have some problems. For one the image is very "heavy" since I must individually plot a huge number of "pixels". Second, I cannot think of any means of changing the color code, like colormap(somemap) does. The color of each individual '.' marker is set at the moment of the plotting, and I have no idea as to how to have it respond to a colormap command.

I'd be really interested in any suggestion on ways of changing the colormap. I thought of using (exceedingly tiny) hexagonal patches instead of markers, but I guess that would make the image even bigger.

Thanks a lot for your help

Francesco