IntExt:

--------------------------------------------------------------------------
   One or two dimensional interpolation and extrapolation. If no outputs
   are given it will plot the interpolated/extrapolated values on the 
   same plot as the matrix a. x and y are assumed to be in order of
   minimum to maximum;
--------------------------------------------------------------------------
   Form:
   c = IntExp( a, x, xC, y, yC )
--------------------------------------------------------------------------

   ------
   Inputs
   ------
   a                      One or two dimensional matrix
   x                      Column values
   xC                     Points at which a is to be computed
   y                      Rows
   yC                     Points at which a is to be computed

   -------
   Outputs
   -------
   c                      Extrapolated/interpolated values

--------------------------------------------------------------------------