      SUBROUTINE PLPRME (XX,Y,N)
C *** SEE R H LANDAU, PROGRAM LPOTT, 1981
C     PLPRME CALCULATES THE DERIV OF THE LEGRENDRE POLYNL,ALL L
      IMPLICIT  REAL*8   (A-H,O-Z)
      DIMENSION Y(50)
      Y(1) = 0.
      Y(2) = 1.
      IF (N.LE.2) RETURN
      DO 10 I=2,N
         Y(I+1) = ((2*I-1.)*XX*Y(I)-I*Y(I-1))/(I-1)
 10   CONTINUE
      RETURN
      END
