plsmaj: Set length of major ticks

plsmaj (def, scale);

This sets up the length of the major ticks. The actual length is the product of the default length and a scaling factor as for character height.

def (PLFLT, input)

The default length of a major 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.

Redacted form: plsmaj(def, scale)

This function is used in example 29.