SLATEC Routines --- D9CHU ---

*DECK D9CHU
      DOUBLE PRECISION FUNCTION D9CHU (A, B, Z)
C***BEGIN PROLOGUE  D9CHU
C***SUBSIDIARY
C***PURPOSE  Evaluate for large Z  Z**A * U(A,B,Z) where U is the
C            logarithmic confluent hypergeometric function.
C***LIBRARY   SLATEC (FNLIB)
C***CATEGORY  C11
C***TYPE      DOUBLE PRECISION (R9CHU-S, D9CHU-D)
C***KEYWORDS  FNLIB, LOGARITHMIC CONFLUENT HYPERGEOMETRIC FUNCTION,
C             SPECIAL FUNCTIONS
C***AUTHOR  Fullerton, W., (LANL)
C***DESCRIPTION
C
C Evaluate for large Z  Z**A * U(A,B,Z)  where U is the logarithmic
C confluent hypergeometric function.  A rational approximation due to Y.
C L. Luke is used.  When U is not in the asymptotic region, i.e., when A
C or B is large compared with Z, considerable significance loss occurs.
C A warning is provided when the computed result is less than half
C precision.
C
C***REFERENCES  (NONE)
C***ROUTINES CALLED  D1MACH, XERMSG
C***REVISION HISTORY  (YYMMDD)
C   770801  DATE WRITTEN
C   890531  Changed all specific intrinsics to generic.  (WRB)
C   890531  REVISION DATE from Version 3.2
C   891214  Prologue converted to Version 4.0 format.  (BAB)
C   900315  CALLs to XERROR changed to CALLs to XERMSG.  (THJ)
C   900720  Routine changed from user-callable to subsidiary.  (WRB)
C***END PROLOGUE  D9CHU