Combination SURF/CONTOUR plot.

  SURFC(...) is the same as SURF1F43EU2(...) except that a contour plot

  is drawn beneath the surface.



  Because CONTOURXAOYTS does not handle irregularly spaced data, this 

  routine only works for surfaces defined on a rectangular grid.

  The matrices or vectors X and Y define the axis limits only.



  See also SURF1F43EU2.