The bounds of an NDF section cannot be altered while any of its array components (or any of its axis arrays) is mapped for access through the identifier supplied to this routine.
The bounds of a base NDF cannot be altered while any part of any of its array components (or any of its axis arrays) is mapped for access, even through another identifier.
The pixel values of any defined NDF array component will be retained if those pixels lie
within both the old and new bounds. Any pixels lying outside the new bounds will be
lost and cannot later be recovered by further changes to the NDF
’s bounds. Any new
pixels introduced where the new bounds extend beyond the old ones will be assigned
" value, and subsequent enquiries about the presence of bad pixels will reflect
If the new NDF bounds extend beyond the bounds of the associated base NDF and any
of the NDF
’s axis arrays have defined values, then these values will be extrapolated as
If the bounds of a base NDF are to be altered and retention of the pixel values of any of its components is not required, then a call to NDF_RESET should be made before calling this routine. This will eliminate any unnecessary processing which might be needed to retain the existing values. This step is not necessary with an NDF section, as no processing of pixel values takes place in this case.