# derf.f

          DOUBLE PRECISION FUNCTION DERF (X)
    C***BEGIN PROLOGUE  DERF
    C***PURPOSE  Compute the error function.
    C***LIBRARY   SLATEC (FNLIB)
    C***CATEGORY  C8A, L5A1E
    C***TYPE      DOUBLE PRECISION (ERF-S, DERF-D)
    C***KEYWORDS  ERF, ERROR FUNCTION, FNLIB, SPECIAL FUNCTIONS
    C***AUTHOR  Fullerton, W., (LANL)
    C***DESCRIPTION
    C
    C DERF(X) calculates the double precision error function for double
    C precision argument X.
    C
    C Series for ERF        on the interval  0.          to  1.00000E+00
    C                                        with weighted error   1.28E-32
    C                                         log weighted error  31.89
    C                               significant figures required  31.05
    C                                    decimal places required  32.55
    C
    C***REFERENCES  (NONE)
    C***ROUTINES CALLED  D1MACH, DCSEVL, DERFC, INITDS
    C***REVISION HISTORY  (YYMMDD)
    C   770701  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   900727  Added EXTERNAL statement.  (WRB)
    C   920618  Removed space from variable name.  (RWC, WRB)
    C***END PROLOGUE  DERF