# r9chu.f

          FUNCTION R9CHU (A, B, Z)
    C***BEGIN PROLOGUE  R9CHU
    ....
    ....
    Warning:   this routine is not intended to be user-callable.
    ....
    ....
    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      SINGLE 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  R1MACH, XERMSG
    C***REVISION HISTORY  (YYMMDD)
    C   770801  DATE WRITTEN
    C   890206  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  R9CHU