Function surfc is similar to surf but its coloring is determined by another data.
MGL code:
call 'prepare2d' title 'SurfC plot':rotate 50 60:light on:box:surfc a b
C++ code:
void smgl_surfc(mglGraph *gr) { mglData a,b; mgls_prepare2d(&a,&b); if(big!=3) gr->Title("SurfC plot"); gr->Rotate(50,60); gr->Light(true); gr->Box(); gr->SurfC(a,b); }