These filter have not be tested thoroughly due to lack of vanilla metafiles and
interpreters. However, while testing the filters on Sun phigs' metafiles an
interesting anomaly was noted. The Sun phigs' CGM generator produces a 
metafile made up exclusively of "long data format" CGM elements. Instructions
that were meant to be contained in "short" elements were coded as longs. This
presents no problem for a "true" CGM interpreter such as Ctrans. However, I
suspect that the Sun phigs' interpreter expects all instructions in the "long"
format to ease translation. The filter for NCAR-format-to-vanilla will
translate "short" instructions to "short" instructions. Thus it is unlikely
that an NCAR CGM filtered to vanilla CGM could be interpreted by the Sun phigs'
interpreter. Other vendors of CGM translators and interpreters may take similar
short cuts.
