r9ln2r.f
FUNCTION R9LN2R (X)
C***BEGIN PROLOGUE R9LN2R
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Warning: this routine is not intended to be user-callable.
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C***SUBSIDIARY
C***PURPOSE Evaluate LOG(1+X) from second order relative accuracy so
C that LOG(1+X) = X - X**2/2 + X**3*R9LN2R(X).
C***LIBRARY SLATEC (FNLIB)
C***CATEGORY C4B
C***TYPE SINGLE PRECISION (R9LN2R-S, D9LN2R-D, C9LN2R-C)
C***KEYWORDS ELEMENTARY FUNCTIONS, FNLIB, LOGARITHM, SECOND ORDER
C***AUTHOR Fullerton, W., (LANL)
C***DESCRIPTION
C
C Evaluate LOG(1+X) from 2-nd order with relative error accuracy so
C that LOG(1+X) = X - X**2/2 + X**3*R9LN2R(X)
C
C Series for LN21 on the interval -6.25000D-01 to 0.
C with weighted error 2.49E-17
C log weighted error 16.60
C significant figures required 15.87
C decimal places required 17.31
C
C Series for LN22 on the interval 0. to 8.12500D-01
C with weighted error 1.42E-17
C log weighted error 16.85
C significant figures required 15.95
C decimal places required 17.50
C
C***REFERENCES (NONE)
C***ROUTINES CALLED CSEVL, INITS, R1MACH, XERMSG
C***REVISION HISTORY (YYMMDD)
C 780401 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 900315 CALLs to XERROR changed to CALLs to XERMSG. (THJ)
C 900720 Routine changed from user-callable to subsidiary. (WRB)
C***END PROLOGUE R9LN2R