## Copyright (C) 2002, 2008 Paul Kienzle
##
## This program 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 3 of the License, or (at
## your option) any later version.
##
## This program 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 this program; see the file COPYING.  If not, see
## <http://www.gnu.org/licenses/>.

## -*- texinfo -*-
## @deftypefn {Function File} {} dlmwrite (@var{file}, @var{a})
## @deftypefnx {Function File} {} dmlwrite (@var{file}, @var{a}, @var{delim}, @var{r}, @var{c})
## @deftypefnx {Function File} {} dmlwrite (@var{file}, @var{a}, "attrib1", @var{value1}, "attrib2", @var{value2}, @dots{})
## @deftypefnx {Function File} {} dmlwrite (@var{file}, @var{a}, "-append", @dots{})
##
## Write the matrix @var{a} to the text @var{file} using delimiters.
##
## @table @var
## @item delim
## the delimiter to use to separate values on a row
##
## @item r
## the number of delimiter-only lines to add to the start of the file
##
## @item c
## the number of delimiters to prepend to each line of data.
##
## @item "-append"
## append to the end of the @var{file}.
##
## @item "append", state
## Either @samp{"on"} or @samp{"off"}.  See @samp{"-append"} above.
##
## @item "delimiter", d
## See @var{delim} above.
##
## @item "newline", os
## The character(s) to use to separate each row.  Three special cases
## exist for this option.  @samp{"unix"} is changed into '\n',
## @samp{"pc"} is changed into '\r\n', and @samp{"mac"} is changed
## into '\r'.  Other values for this option are kept as is.
##
## @item "roffset", r
## See @var{r} above.
##
## @item "coffset", c
## See @var{c} above.
##
## @item "precision", p
## The precision to use when writing the file.  It can either be a
## format string (as used by fprintf) or a number of significant digits.
## @end table
##
## @example
## @var{A} = reshape(1:16,4,4);
## dlmwrite(@code{"file.csv"}, @var{A})
## @end example
##
## @example
## dlmwrite (@code{"file.tex"}, @var{a}, "delimiter", "&", "newline", "\\n")
## @end example
##
## @seealso{dlmread, csvread, csvwrite}
## @end deftypefn

## Author: Paul Kienzle <pkienzle@users.sf.net>
## 
## This program was originally granted to the public domain
## 
## 2002-03-08 Paul Kienzle <pkienzle@users.sf.net>
## * Initial revision
## 2005-11-27 Bill Denney <bill@givebillmoney.com>
## * Significant modifications of the input arguements for additional
## functionality.

function dlmwrite (file, a, varargin)

  if (nargin < 2 || ! ischar (file))
    ptint_usage ();
  endif

  ## set defaults
  delim = ",";
  r = 0;
  c = 0;
  newline = "\n";
  precision = "%.16g";
  opentype = "wt";

  ## process the input arguements
  i = 0;
  while (i < length (varargin))
    i = i + 1;
    if (strcmpi (varargin{i}, "delimiter") || strcmpi(varargin{i}, "delim"))
      i = i + 1;
      delim = varargin{i};
    elseif (strcmpi (varargin{i}, "newline"))
      i = i + 1;
      newline = varargin{i};
      if (strcmpi (newline, "unix"))
	newline = "\n";
      elseif (strcmpi (newline, "pc"))
	newline = "\r\n";
      elseif (strcmpi (newline, "mac"))
	newline = "\r";
      endif
    elseif (strcmpi (varargin{i}, "roffset"))
      i = i + 1;
      r = varargin{i};
    elseif (strcmpi (varargin{i}, "coffset"))
      i = i + 1;
      c = varargin{i};
    elseif (strcmpi (varargin{i}, "precision"))
      i = i + 1;
      precision = varargin{i};
      if (! strcmpi (class (precision), "char"))
	precision = sprintf ("%.%gg", precision);
      endif
    elseif (strcmpi (varargin{i}, "-append"))
      opentype = "at";
    elseif (strcmpi (varargin{i}, "append"))
      i = i + 1;
      if (strcmpi (varargin{i}, "on"))
	opentype = "at";
      elseif (strcmpi (varargin{i}, "off"))
	opentype = "wt";
      else
	error ("dlmwrite: append must be \"on\" or \"off\".");
      endif
    else
      if (i == 1)
	delim = varargin{i};
      elseif (i == 2)
	r = varargin{i};
      elseif (i == 3)
	c = varargin{i};
      else
	print_usage();
      endif
    endif
  endwhile

  [fid, msg] = fopen (file, opentype);
  if (fid < 0)
    error (msg);
  else
    if (r > 0)
      fprintf (fid, "%s",
	       repmat ([repmat(delim, 1, c + columns(a)-1), newline], 1, r));
    endif
    if (iscomplex (a))
      cprecision = regexprep (precision, '^%([-\d.])','%+$1');
      template = [precision, cprecision, "i", ...
		  repmat([delim, precision, cprecision, "i"], 1, ...
		  columns(a) - 1), newline ];
    else
      template = [precision, repmat([delim, precision], 1, columns(a)-1),...
		  newline];
    endif
    if (c > 0)
      template = [repmat(delim, 1, c), template];
    endif
    if (iscomplex (a))
      a = a.';
      b = zeros (2*rows(a), columns (a));
      b(1: 2 : end, :) = real (a);
      b(2: 2 : end, :) = imag (a);
      fprintf (fid, template, b);
    else
      fprintf (fid, template, a.');
    endif
    fclose (fid);
  endif
endfunction

%!test
%! f = tmpnam();
%! dlmwrite(f,[1,2;3,4],'precision','%5.2f','newline','unix','roffset',1,'coffset',1);
%! fid = fopen(f,"rt");
%! f1 = char(fread(fid,Inf,'char')');
%! fclose(fid);
%! dlmwrite(f,[5,6],'precision','%5.2f','newline','unix','coffset',1,'delimiter',',','-append');
%! dlmwrite(f,[5,6],'precision','%5.2f','delim','\t','-append');
%! fid = fopen(f,"rt");
%! f2 = char(fread(fid,Inf,'char')');
%! fclose(fid);
%! unlink(f);
%!
%! assert(f1,",,\n, 1.00, 2.00\n, 3.00, 4.00\n");
%! assert(f2,",,\n, 1.00, 2.00\n, 3.00, 4.00\n, 5.00, 6.00\n 5.00\t 6.00\n");