R9LN2R(3)

SYNOPSIS
FUNCTION R9LN2R (X)

NAME
r9ln2r - Evaluate LOG(1+X) from second order relative accuracy so that LOG(1+X) = X - X**2/2 + X**3*R9LN2R(X).

LIBRARY
SLATEC (FNLIB)

CATEGORY
C4B

TYPE
SINGLE PRECISION (R9LN2R-S, D9LN2R-D, C9LN2R-C)

KEYWORDS
ELEMENTARY FUNCTIONS, FNLIB, LOGARITHM, SECOND ORDER

AUTHOR
Fullerton, W., (LANL)

DESCRIPTION
Evaluate LOG(1+X) from 2-nd order with relative error accuracy so that LOG(1+X) = X - X**2/2 + X**3*R9LN2R(X) Series for LN21 on the interval -6.25000D-01 to 0. with weighted error 2.49E-17 log weighted error 16.60 significant figures required 15.87 decimal places required 17.31 Series for LN22 on the interval 0. to 8.12500D-01 with weighted error 1.42E-17 log weighted error 16.85 significant figures required 15.95 decimal places required 17.50

REFERENCES
(NONE)

ROUTINES CALLED
CSEVL, INITS, R1MACH, XERMSG

REVISION HISTORY (YYMMDD)
780401 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)
900720 Routine changed from user-callable to subsidiary. (WRB)