The routine resets a component of an NDF so that its value becomes undefined. It may be used to remove unwanted optional NDF components. Its use is also advisable before making format changes to an NDF if retention of the existing values is not required (e.g. before changing the data type of an array component with the NDF_STYPE routine); this will avoid the cost of converting the existing values.

CALL NDF_RESET( INDF, COMP, STATUS )

INDF = INTEGER (Given)

COMP = CHARACTER $\ast$ ( $\ast$ ) (Given)

STATUS = INTEGER (Given and Returned)

• A comma-separated list of component names may also be supplied in which case each component will be reset in turn.

• Specifying a component name of ’$\ast$’ will cause all components, except for HISTORY and extensions, to be reset. The former may be reset by specifying its name explicitly, while all extensions may be removed by specifying a component name of ’EXTENSION’.

• Individual extensions may be removed from an NDF with the NDF_XDEL routine.

• This routine may only be used to reset components of a base NDF. If an NDF section is supplied, then it will return without action. No error will result.

• An array component of an NDF cannot be reset while it is mapped for access. Neither can an NDF’s axis component be reset while any axis array is mapped for access. This routine will fail if either of these conditions occurs.