Subroutine: GDS_EXTEND Purpose: create or extend an axis Category: GDS File: gds_extend.c Author: W. Zwitser Use: GDS_EXTEND( SET, Input character AXNAME, Input character ORIGIN, Input double SIZE, Input integer ERROR ) In/Out integer SET name of set AXNAME name of axis If omitted: last axis. ORIGIN new origin If omitted: extend last axis. SIZE new size If omitted: 1 is assumed for new axis or origin shift of an existing one. ERROR 0 = successful -28 = axis already in use Description: GDS_EXTEND can be used for several purposes: 1. create a new axis. Each call increments descriptor NAXIS with 1. The new value 'n' of NAXIS is used to create 3 new descriptors: - CTYPEn = the name of the new axis - CRPIXn = the origin/reference point of the new axis - NAXISn = the size of the new axis 2. extend the size of the last axis. Now AXNAME and ORIGIN are optional and SIZE will be the new size of the last axis. 3. shift the origin (reference point) of an axis. AXNAME and ORIGIN must be given and SIZE is not allowed. Updates: Dec 21, 1990: WZ, migrated to C Oct 31, 1990: WZ, 'naxis', etc. from setsta -> dsc_file Mar 23, 1994: JPT, modified to cooperate with GDS server.