15.44.10  POINTS|COLUMNS 

Specifies  the  range  of  points  or the colums of a mesh to use.  If not
specified all data points are used.  If n2 is omitted it is assumed to  be
n1.   You may specify the point number or the options FIRST,LAST.  For 3-d
plots this specifies the columns to use in the plot.