[cargresult,z]=carg(z);

function [cargresult,z]=carg(z);
cargresult=[];
persistent carg ; 

if isempty(cargresult), cargresult=0; end;
%***BEGIN PROLOGUE  CARG
%***PURPOSE  Compute the argument of a complex number.
%***LIBRARY   SLATEC (FNLIB)
%***CATEGORY  A4A
%***TYPE      COMPLEX (CARG-C)
%***KEYWORDS  ARGUMENT OF A COMPLEX NUMBER, ELEMENTARY FUNCTIONS, FNLIB
%***AUTHOR  Fullerton, W., (LANL)
%***DESCRIPTION
%
% CARG(Z) calculates the argument of the complex number Z.  Note
% that CARG returns a real result.  If Z = X+iY, then CARG is ATAN(Y/X),
% except when both X and Y are zero, in which case the result
% will be zero.
%
%***REFERENCES  (NONE)
%***ROUTINES CALLED  (NONE)
%***REVISION HISTORY  (YYMMDD)
%   770401  DATE WRITTEN
%   861211  REVISION DATE from Version 3.2
%   891214  Prologue converted to Version 4.0 format.  (BAB)
%***end PROLOGUE  CARG
%***FIRST EXECUTABLE STATEMENT  CARG
cargresult = 0.0;
if( real(z)~=0. || imag(z)~=0. )
cargresult = atan2(imag(z),real(z));
end;
%
csnil=dbstack(1); csnil=csnil(1).name(1)~='@';
if csnil&&~isempty(inputname(1)), assignin('caller','FUntemp',z); evalin('caller',[inputname(1),'=FUntemp;']); end
end
%DECK CASIN