The routines described below have been rendered obsolete by developments in the NDF_ library and should not be used in new software. They are included here simply as an aid to understanding existing software which uses them, and to allow them to be replaced with alternative techniques as the opportunity arises. These routines will eventually be removed from the NDF_ documentation and may, in some cases, eventually be eliminated from the library altogether.

The reason for obsolescence is indicated in each case.