 
      DOUBLE PRECISION FUNCTION DCHU(A,B,X)
C***BEGIN PROLOGUE  DCHU
C***DATE WRITTEN   770801   (YYMMDD)
C***REVISION DATE  820801   (YYMMDD)
C***CATEGORY NO.  C11
C***KEYWORDS  CONFLUENT HYPERGEOMETRIC FUNCTION,DOUBLE PRECISION,
C             LOGARITHMIC,SPECIAL FUNCTION
C***AUTHOR  FULLERTON, W., (LANL)
C***PURPOSE  Calculates the d.p. logarithmic confluent hypergeometric
C            function.
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***REFERENCES  (NONE)
C***ROUTINES CALLED  D1MACH,D9CHU,DEXPRL,DGAMMA,DGAMR,DINT,DPOCH,DPOCH1,
C                    XERROR
C***END PROLOGUE  DCHU
 
 
