DLNREL(3)

SYNOPSIS
DOUBLE PRECISION FUNCTION DLNREL (X)

NAME
dlnrel - Evaluate ln(1+X) accurate in the sense of relative error.

LIBRARY
SLATEC (FNLIB)

CATEGORY
C4B

TYPE
DOUBLE PRECISION (ALNREL-S, DLNREL-D, CLNREL-C)

KEYWORDS
ELEMENTARY FUNCTIONS, FNLIB, LOGARITHM

AUTHOR
Fullerton, W., (LANL)

DESCRIPTION
DLNREL(X) calculates the double precision natural logarithm of (1.0+X) for double precision argument X. This routine should be used when X is small and accurate to calculate the logarithm accurately (in the relative error sense) in the neighborhood of 1.0. Series for ALNR on the interval -3.75000E-01 to 3.75000E-01 with weighted error 6.35E-32 log weighted error 31.20 significant figures required 30.93 decimal places required 32.01

REFERENCES
(NONE)

ROUTINES CALLED
D1MACH, DCSEVL, INITDS, XERMSG

REVISION HISTORY (YYMMDD)
770601 DATE WRITTEN
890531 Changed all specific intrinsics to generic. (WRB)
890531 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)