numeric variable name;
returns the index of the marker type currently selected. See
the function MARTYPE for an explanation of the indexes for markers.
The GASK('MARTYPE',
. . . ) routine returns the current marker type. If no marker type
has been previously selected with the GSET('MARTYPE', . . . ) function,
GASK('MARTYPE', . . . ) returns the default value, 1.