SUBROUTINE  PLTTH (X,Y,P)

C     [TOP HALF]
C     SCALE THE CARTESIAN COORDINATES X,Y SO AS TO PLACE A GRAPH
C     IN THE TOP HALF OF A PLOTTER PAGE.
C     [20-APR-74]

      LOGICAL*1     P
      DATA        HX,HY/4.50,3.25/

      CALL PLTMS (HX*Y,2.0*HY*(0.5-X),P)
      RETURN

      END