Function:     W

Purpose:      Error function for complex arguments.
              W(Z) = EXP(-Z*Z)ERFC(-iZ)

Category:

Files:        w.c

Author:       Kor G. Begeman

Use:          COMPLEX W(Z)          Input      COMPLEX

              W         The function value
              Z         Complex argument

Method:       see Abromowitz and Stegun (chapter 7)
                                - 6
Precision:    |error|  <  2 * 10

Updates:      Dec  2, 1982 : KGB creation date
              Apr 28, 1986 : KGB migrated to VAX-VMS
              Nov 26, 1992 : KGB Migrated to UNIX-GIPSY