## Copyright (C) 1998 Auburn University.  All rights reserved.
##
## This file is part of Octave.
##
## Octave is free software; you can redistribute it and/or modify it
## under the terms of the GNU General Public License as published by the
## Free Software Foundation; either version 2, or (at your option) any
## later version.
##
## Octave is distributed in the hope that it will be useful, but WITHOUT
## ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
## FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
## for more details.
##
## You should have received a copy of the GNU General Public License
## along with Octave; see the file COPYING.  If not, write to the Free
## Software Foundation, 59 Temple Place, Suite 330, Boston, MA 02111 USA.

## -*- texinfo -*-
## @deftypefn {Function File} {} com2str (@var{zz}, @var{flg})
##
## convert complex number to a string
## @strong{Inputs}
## @table @var
## @item zz
## complex number
## @item flg
## format flag
## 0 (default):            -1, 0, 1,   1i,   1 + 0.5i
## 1 (for use with zpout): -1, 0, + 1, + 1i, + 1 + 0.5i
## @end table
## @end deftypefn

function retval = com2str (zz, flg)

  if (nargin < 1 || nargin > 2)
    usage ("com2str (zz, flg)");
  endif
  if (nargin == 1)
    flg = 0;
  endif

  if (! (is_scalar (zz) && is_scalar (flg)))
    error ("com2str: arguments must be a scalar");
  endif

  if (flg != 0 && flg != 1)
    error ("invalid flg value: %d", flg);
  endif

  sgns = "+-";
  rz = real (zz);
  iz = imag (zz);
  az = abs (zz);
  if (iz == 0)
    ## strictly a real number
    switch (flg)
      case(0)
	retval = num2str (rz);
      case(1)
	retval = [sgns(1+(rz<0)), " ", num2str(abs(rz))];
    endswitch
  elseif (rz == 0)
    ## strictly an imaginary number
    switch (flg)
      case(0)
	retval = num2str (iz);
      case(1)
	retval = [sgns(1+(iz<0)), " ", num2str(abs(iz)), "i"];
    endswitch
  else
    ## complex number
    ## strictly an imaginary number
    switch (flg)
      case(0)
	retval = [num2str(rz), " ", com2str(i*iz,1)];
      case(1)
	retval = [sgns(1+(rz<0)), " ", num2str(abs(rz)), " ", com2str(i*iz,1)];
    endswitch
  endif

endfunction