SLATEC Routines --- XPSI ---

*DECK XPSI
      REAL FUNCTION XPSI (A, IPSIK, IPSIX)
C***BEGIN PROLOGUE  XPSI
C***SUBSIDIARY
C***PURPOSE  To compute values of the Psi function for XLEGF.
C***LIBRARY   SLATEC
C***CATEGORY  C7C
C***TYPE      SINGLE PRECISION (XPSI-S, DXPSI-D)
C***KEYWORDS  PSI FUNCTION
C***AUTHOR  Smith, John M., (NBS and George Mason University)
C***ROUTINES CALLED  (NONE)
C***REVISION HISTORY  (YYMMDD)
C   820728  DATE WRITTEN
C   890126  Revised to meet SLATEC CML recommendations.  (DWL and JMS)
C   901019  Revisions to prologue.  (DWL and WRB)
C   901106  Changed all specific intrinsics to generic.  (WRB)
C           Corrected order of sections in prologue and added TYPE
C           section.  (WRB)
C   920127  Revised PURPOSE section of prologue.  (DWL)
C***END PROLOGUE  XPSI