chu.f
FUNCTION CHU (A, B, X)
C***BEGIN PROLOGUE CHU
C***PURPOSE Compute the logarithmic confluent hypergeometric function.
C***LIBRARY SLATEC (FNLIB)
C***CATEGORY C11
C***TYPE SINGLE PRECISION (CHU-S, DCHU-D)
C***KEYWORDS FNLIB, LOGARITHMIC CONFLUENT HYPERGEOMETRIC FUNCTION,
C SPECIAL FUNCTIONS
C***AUTHOR Fullerton, W., (LANL)
C***DESCRIPTION
C
C CHU computes the logarithmic confluent hypergeometric function,
C U(A,B,X).
C
C Input Parameters:
C A real
C B real
C X real and positive
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 EXPREL, GAMMA, GAMR, POCH, POCH1, R1MACH, R9CHU,
C 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 CHU