# dlnrel.f

          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