SLATEC Routines --- EXPREL ---

*DECK EXPREL
      FUNCTION EXPREL (X)
C***BEGIN PROLOGUE  EXPREL
C***PURPOSE  Calculate the relative error exponential (EXP(X)-1)/X.
C***LIBRARY   SLATEC (FNLIB)
C***CATEGORY  C4B
C***TYPE      SINGLE PRECISION (EXPREL-S, DEXPRL-D, CEXPRL-C)
C***KEYWORDS  ELEMENTARY FUNCTIONS, EXPONENTIAL, FIRST ORDER, FNLIB
C***AUTHOR  Fullerton, W., (LANL)
C***DESCRIPTION
C
C Evaluate  EXPREL(X) = (EXP(X) - 1.0) / X.   For small ABS(X) the
C Taylor series is used.  If X is negative, the reflection formula
C         EXPREL(X) = EXP(X) * EXPREL(ABS(X))
C may be used.  This reflection formula will be of use when the
C evaluation for small ABS(X) is done by Chebyshev series rather than
C Taylor series.  EXPREL and X are single precision.
C
C***REFERENCES  (NONE)
C***ROUTINES CALLED  R1MACH
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***END PROLOGUE  EXPREL