red to yellow colormap
cmap=hotcolormap(n)
:n integer >= 3, the colormap size. : :cmap matrix with 3 columns [R,G,B]. :
hotcolormap computes a colormap with n hot colors varying from red to yellow.
f = `scf`_();
`plot3d1`_();
f.color_map = hotcolormap(32);