SLATEC Routines --- DLNREL ---

*DECK DLNREL
      DOUBLE PRECISION FUNCTION DLNREL (X)
C***BEGIN PROLOGUE  DLNREL
C***PURPOSE  Evaluate ln(1+X) accurate in the sense of relative error.
C***LIBRARY   SLATEC (FNLIB)
C***CATEGORY  C4B
C***TYPE      DOUBLE PRECISION (ALNREL-S, DLNREL-D, CLNREL-C)
C***KEYWORDS  ELEMENTARY FUNCTIONS, FNLIB, LOGARITHM
C***AUTHOR  Fullerton, W., (LANL)
C***DESCRIPTION
C
C DLNREL(X) calculates the double precision natural logarithm of
C (1.0+X) for double precision argument X.  This routine should
C be used when X is small and accurate to calculate the logarithm
C accurately (in the relative error sense) in the neighborhood
C of 1.0.
C
C Series for ALNR       on the interval -3.75000E-01 to  3.75000E-01
C                                        with weighted error   6.35E-32
C                                         log weighted error  31.20
C                               significant figures required  30.93
C                                    decimal places required  32.01
C
C***REFERENCES  (NONE)
C***ROUTINES CALLED  D1MACH, DCSEVL, INITDS, XERMSG
C***REVISION HISTORY  (YYMMDD)
C   770601  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***END PROLOGUE  DLNREL