NDF Size

The size of an NDF is the total number of pixels lying within its bounds, and is given by the product of the sizes of all its dimensions. Many applications require only this information about an NDF's shape and can conveniently obtain it using the routine NDF_SIZE, as follows:

      CALL NDF_SIZE( INDF, NPIX, STATUS )

This routine returns the total number of pixels via its integer argument NPIX. Note, however, that this same quantity is also returned as a by-product of most routines which directly access the array components of an NDF (see §, for example), so a call to NDF_SIZE can often be avoided.