
plsmin: Set length of minor ticks 

DESCRIPTION:

    This function is used in example 29. 

SYNOPSIS:

plsmin(def, scale)

ARGUMENTS:

    def (PLFLT, input) :    The default length of a minor tick in
    millimeters, should be set to zero if the default length is to
    remain unchanged. 

    scale (PLFLT, input) :    Scale factor to be applied to default to get
    actual tick length. 
