R9CHU(3)

SYNOPSIS
FUNCTION R9CHU (A, B, Z)

NAME
r9chu - Evaluate for large Z Z**A * U(A,B,Z) where U is the logarithmic confluent hypergeometric function.

LIBRARY
SLATEC (FNLIB)

CATEGORY
C11

TYPE
SINGLE PRECISION (R9CHU-S, D9CHU-D)

KEYWORDS
FNLIB, LOGARITHMIC CONFLUENT HYPERGEOMETRIC FUNCTION, SPECIAL FUNCTIONS

AUTHOR
Fullerton, W., (LANL)

DESCRIPTION
Evaluate for large Z Z**A * U(A,B,Z) where U is the logarithmic confluent hypergeometric function. A rational approximation due to Y. L. Luke is used. When U is not in the asymptotic region, i.e., when A or B is large compared with Z, considerable significance loss occurs. A warning is provided when the computed result is less than half precision.

REFERENCES
(NONE)

ROUTINES CALLED
R1MACH, XERMSG

REVISION HISTORY (YYMMDD)
770801 DATE WRITTEN
890206 REVISION DATE from Version 3.2
891214 Prologue converted to Version 4.0 format. (BAB)
900315 CALLs to XERROR changed to CALLs to XERMSG. (THJ)
900720 Routine changed from user-callable to subsidiary. (WRB)