EXPAND procedure shrinks or expands a two-dimensional
array, using bilinear interpolation. It is similar to the CONGRID and REBIN routines.
This routine is written in the IDL language. Its source code can be found in the file
subdirectory of the IDL distribution.
A, Nx, Ny, Result
A two-dimensional array to be magnified.
Desired size of the X dimension, in pixels.
Desired size of the Y dimension, in pixels.
A named variable that will contain the magnified array.
Set this keyword equal to the largest good value. Elements greater than this value are set equal to the value of the FILLVAL keyword.
Set this keyword equal to the value to use when elements larger than MAXVAL are encountered. The default is -1.