This attribute selects the
routines which are used to draw graphics by the
Plot class. If it is zero, then the routines in
the graphics interface selected at link-time are used (see the
ast_link script). Otherwise,
routines registered using
AST_GRFSET are used. In this case, if a routine is needed which
has not been registered, then the routine in the graphics interface selected at link-time is
used.
The default is to use the graphics interface
Plot
All Plots
have this attribute.
The Plot3D class ignores this attributes, assuming a value of zero.