 
      FUNCTION ERF (X)
C***BEGIN PROLOGUE  ERF
C***DATE WRITTEN   770401   (YYMMDD)
C***REVISION DATE  820801   (YYMMDD)
C***CATEGORY NO.  C8A,L5A1E
C***KEYWORDS  ERF,ERROR FUNCTION,SPECIAL FUNCTION
C***AUTHOR  FULLERTON, W., (LANL)
C***PURPOSE  Computes the error function, ERF.
C***DESCRIPTION
C ERF(X) calculates the single precision error function for
C single precision argument X.
C
C Series for ERF        on the interval  0.          to  1.00000D+00
C                                        with weighted error   7.10E-18
C                                         log weighted error  17.15
C                               significant figures required  16.31
C                                    decimal places required  17.71
C***REFERENCES  (NONE)
C***ROUTINES CALLED  CSEVL,ERFC,INITS,R1MACH
C***END PROLOGUE  ERF
 
 
