numeric constant or
numeric variable name; indicates the index of the marker to draw.
Valid values are 1 to 67, inclusive. See Symbol Indexes Used with DSGI for value specifications.
The GSET('MARTYPE',
. . . ) function determines the type of marker drawn. See Special Symbols for Plotting Data Points for representations
of the symbols described in Symbol Indexes Used with DSGI. The aspect source flag (ASF) of MARTYPE must be set to
'INDIVIDUAL' for this attribute to be used outside of a marker bundle.