cexprl.f
COMPLEX FUNCTION CEXPRL (Z)
C***BEGIN PROLOGUE CEXPRL
C***PURPOSE Calculate the relative error exponential (EXP(X)-1)/X.
C***LIBRARY SLATEC (FNLIB)
C***CATEGORY C4B
C***TYPE COMPLEX (EXPREL-S, DEXPRL-D, CEXPRL-C)
C***KEYWORDS ELEMENTARY FUNCTIONS, EXPONENTIAL, FIRST ORDER, FNLIB
C***AUTHOR Fullerton, W., (LANL)
C***DESCRIPTION
C
C Evaluate (EXP(Z)-1)/Z . For small ABS(Z), we use the Taylor
C series. We could instead use the expression
C CEXPRL(Z) = (EXP(X)*EXP(I*Y)-1)/Z
C = (X*EXPREL(X) * (1 - 2*SIN(Y/2)**2) - 2*SIN(Y/2)**2
C + I*SIN(Y)*(1+X*EXPREL(X))) / Z
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 CEXPRL