Synonyms for Attribute Names

The available plotting attributes and their names are defined by the AST subroutine library (see SUN/210) upon which KAPPA graphics are based (together with PGPLOT ). However, KAPPA provides synonyms for certain plotting attributes where this would provide a clearer indication of the purpose of the attribute within the context of a particular application. These synonyms are listed in the description of the STYLE parameter for the particular applications concerned. For instance, the CONTOUR applications draws contours as `curves', that is, it uses the attributes Colour(Curves), Width(Curves) and Style(Curves) to determine the appearance of the contours. However, the synonym Contours (minimum abbreviation Cont) may be used in place of Curves, so the appearance of the contours can also be specified using the `pseudo-' attributes Colour(Cont), Width(Cont) and Style(Cont).

You should remember that a synonym is simply an alternative way of specifying a particular attribute. So if you are running CONTOUR and you give the two setting strings:

   Colour(cont)=red
   Colour(curve)=blue

the contours will appear blue, not red, because the second attribute setting overrides the first one.

Any particular synonym will only be recognised by certain applications. Thus, Contours is only recognised as a synonym for Curves when running CONTOUR. Applications ignore attributes (or synonyms) which they do not recognise, without reporting an error. Thus if the file containing your default plotting style (used by all applications--see later) contains the two lines:

   Colour(curve)=blue
   Colour(cont)=red

then CONTOUR will draw contours in red, but other applications will draw their curves in blue since they ignore the Colour(cont)=red line. Note, if these two lines were the other way round:

   Colour(cont)=red
   Colour(curve)=blue

then all curves, including contours drawn by CONTOUR, would be blue. This is because CONTOUR will process both lines in the order supplied, ending up with blue contours.