Function:     PGEXIST

Purpose:      Test whether a Hershey symbol, with index between
              1..3000, exists

Category:     GRAPHICS

File:         pgplot.src

Author:       M.G.R. Vogelaar

Use:          INTEGER PGEXIST( N )         Input      INTEGER

Description:  PGPLOT uses Hershey symbols for two `primitive' operations:
              graph markers and text.  The Hershey symbol set includes 
              several hundred different symbols in a digitized form that 
              allows them to be drawn with a series of vectors (polylines).
              The routine PGEXIST has an integer argument between 1 and
              3000. It returns 1 if the symbol exists and 0 if it does
              not exist.

Updates:      Dec 23, 1994: VOG Document created.
              Oct 12, 2001: JPT Fixed common block layout.