*H

This operation takes a real number from the top of the stack. It then adjusts the plot minimum (see PMIN) and the plot maximum (see PMAX) so that the current center of the plot is preserved but the height of the plot is multiplied by the factor specified. A value greater than 1 will result in the plot height increasing while a value less than 1 will decrease the plot height. The current Y values for the plot minimum and the plot maximum will change accordingly but the X values will be preserved.

If PPAR exists, its values are read, the new plot minimum and maximum is calculated and then PPAR is stored, overwriting its old values. If PPAR does not exist, then default values are used, the plot view height is recalculated and then PPAR is stored.