dchu.f
DOUBLE PRECISION FUNCTION DCHU (A, B, X)
C***BEGIN PROLOGUE DCHU
C***PURPOSE Compute the logarithmic confluent hypergeometric function.
C***LIBRARY SLATEC (FNLIB)
C***CATEGORY C11
C***TYPE DOUBLE PRECISION (CHU-S, DCHU-D)
C***KEYWORDS FNLIB, LOGARITHMIC CONFLUENT HYPERGEOMETRIC FUNCTION,
C SPECIAL FUNCTIONS
C***AUTHOR Fullerton, W., (LANL)
C***DESCRIPTION
C
C DCHU(A,B,X) calculates the double precision logarithmic confluent
C hypergeometric function U(A,B,X) for double precision arguments
C A, B, and X.
C
C This routine is not valid when 1+A-B is close to zero if X is small.
C
C***REFERENCES (NONE)
C***ROUTINES CALLED D1MACH, D9CHU, DEXPRL, DGAMMA, DGAMR, DPOCH,
C DPOCH1, 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 900727 Added EXTERNAL statement. (WRB)
C***END PROLOGUE DCHU