SUBROUTINE XDPQNU(NU1,NU2,MU,THETA,ID,PQA,IPQA)
C***BEGIN PROLOGUE  XDPQNU
C***REFER TO  XDLEGF
C***ROUTINES CALLED  XDADD, XDADJ, XDPSI
C***COMMON BLOCKS    XDBLK1
C***DATE WRITTEN   820728   (YYMMDD)
C***REVISION DATE  871119   (YYMMDD)
C***CATEGORY NO.  C3A2,C9
C***KEYWORDS  LEGENDRE FUNCTIONS
C***AUTHOR  SMITH, JOHN M. (NBS AND GEORGE MASON UNIVERSITY)
C***PURPOSE  TO COMPUTE THE VALUES OF LEGENDRE FUNCTIONS FOR XDLEGF.
C        SUBROUTINE XDPQNU CALCULATES INITIAL VALUES OF P OR Q
C        USING POWER SERIES.  THEN XDPQNU PERFORMS FORWARD NU-WISE
C        RECURRENCE TO OBTAIN P(-MU,NU,X), Q(0,NU,X), OR Q(1,NU,X).
C        THE FORWARD NU-WISE RECURRENCE IS STABLE FOR P FOR ALL
C        VALUES OF MU, AND IS STABLE FOR Q FOR MU=0 OR 1.
C***REFERENCES  OLVER AND SMITH,J.COMPUT.PHYSICS,51(1983),N0.3,502-518.
C***END PROLOGUE  XDPQNU