The routine returns a logical value indicating whether an array may contain bad pixels for which checks must be made when its values are processed. Only if the returned value is .FALSE. can such checks be omitted. If the CHECK argument to this routine is set .TRUE., then it will perform an explicit check (if necessary) to see whether bad pixels are actually present.

CALL ARY_BAD( IARY, CHECK, BAD, STATUS )

IARY = INTEGER (Given)

CHECK = LOGICAL (Given)

BAD = LOGICAL (Returned)

STATUS = INTEGER (Given and Returned)

• If CHECK is set .FALSE., then the returned value of BAD will indicate whether bad pixels might be present and should therefore be checked for during subsequent processing. However, even if BAD is returned .TRUE. in such circumstances, it is still possible that there may not actually be any bad pixels present (for instance, in an array section, the region of the base array accessed might happen to avoid all the bad pixels).

• If CHECK is set .TRUE., then an explicit check will be made, if necessary, to ensure that BAD is only returned .TRUE. if bad pixels are actually present.

• If the array is mapped for access through the identifier supplied, then the value of BAD will refer to the actual mapped values. It may differ from its original (unmapped) value if conversion errors occurred during the mapping process, or if an initialisation option of ’/ZERO’ was specified for an array which was initially undefined, or if the mapped values have subsequently been modified.

• The BAD argument will always return a value of .TRUE. if the array is in an undefined state.