Next: NDF_BASE - Obtain an identifier for a base NDF
Up: FORTRAN ROUTINE DESCRIPTIONS
Previous: NDF_AUNMP - Unmap an NDF axis array
NDF_BAD
- Determine if an NDF array component may contain bad pixels
- Description:
The routine returns a logical value indicating whether an array
component of an NDF may contain bad pixels for which checks must
be made when the array's 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 also
perform an explicit check (if necessary) to see whether bad
pixels are actually present.
- Invocation:
CALL NDF_BAD( INDF, COMP, CHECK, BAD, STATUS )
- Arguments:
-
INDF = INTEGER (Given)
-
NDF identifier.
-
COMP = CHARACTER * ( * ) (Given)
-
Name of the NDF array component: 'DATA', 'QUALITY' or
'VARIANCE'.
-
CHECK = LOGICAL (Given)
-
Whether to perform an explicit check to see whether bad pixels
are actually present.
-
BAD = LOGICAL (Returned)
-
Whether it is necessary to check for bad pixels when
processing the array's values.
-
STATUS = INTEGER (Given and Returned)
-
The global status.
- Notes:
-
A comma-separated list of component names may also be
supplied, in which case the routine returns the logical "OR" of
the results for each component.
-
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 NDF section, the accessible region of an array
component 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 a component 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, if an
initialisation option of '/ZERO' was specified for a component
whose value was initially undefined, or if the mapped values have
subsequently been modified.
-
A BAD=.TRUE. result will be returned for any components which
are in an undefined state, except in the case of the QUALITY
component for which a .FALSE. result is always returned under
these circumstances.
Next: NDF_BASE - Obtain an identifier for a base NDF
Up: FORTRAN ROUTINE DESCRIPTIONS
Previous: NDF_AUNMP - Unmap an NDF axis array
Starlink User Note 33
R.F. Warren-Smith
11th January 2000
E-mail:rfws@star.rl.ac.uk
Copyright © 2000 Council for the Central Laboratory of the Research Councils