z0= interp2(y0,x0, z,y,x)
-or- z0= interp2(y0,x0, z,y,x,reg)
return the bilinear interpolate of the function Z(X,Y) at the
points (X0,Y0). The X, Y, and optional REG arrays specify a
quadrilateral mesh as for the plm function. The Z values are
specified at the vertices of this mesh, so Z must have the
same dimensions as X and Y.
Points outside the mesh get the value 0.0, unless the outside
keyword is non-nil, in which case they get that value.
interpreted function, defined at i/digit2.i line 36