# 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, 675 Mass Ave, Cambridge, MA 02139, USA. 
 
function retval = com2str(zz,flg)
# usage retval = com2str(zz{,flg})
#  
# convert complex number to a string
# zz: complex number
# flg: format flag
#      0 (default):            -1, 0, 1,   1i,   1 + 0.5i
#      1 (for use with zpout): -1, 0, + 1, + 1i, + 1 + 0.5i
#

  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(["Illegal flg value: ",num2str(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