update packages

[CreaPhase.git] / octave_packages / m / strings / strjust.m

diff --git a/octave_packages/m/strings/strjust.m b/octave_packages/m/strings/strjust.m
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+## Copyright (C) 2000-2012 Paul Kienzle
+## Copyright (C) 2009 Jaroslav Hajek
+##
+## 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 3 of the License, 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, see
+## <http://www.gnu.org/licenses/>.
+
+## -*- texinfo -*-
+## @deftypefn  {Function File} {} strjust (@var{s})
+## @deftypefnx {Function File} {} strjust (@var{s}, @var{pos})
+## Return the text, @var{s}, justified according to @var{pos}, which may
+## be @samp{"left"}, @samp{"center"}, or @samp{"right"}.  If @var{pos}
+## is omitted it defaults to @samp{"right"}.
+##
+## Null characters are replaced by spaces.  All other character
+## data are treated as non-white space.
+##
+## Example:
+##
+## @example
+## @group
+## strjust (["a"; "ab"; "abc"; "abcd"])
+##      @result{}
+##         "   a"
+##         "  ab"
+##         " abc"
+##         "abcd"
+## @end group
+## @end example
+## @seealso{deblank, strrep, strtrim, untabify}
+## @end deftypefn
+
+function y = strjust (s, pos = "right")
+
+  if (nargin < 1 || nargin > 2)
+    print_usage ();
+  elseif (! ischar (s) || ndims (s) > 2)
+    error ("strjust: S must be a string or 2-D character matrix");
+  endif
+
+  if (isempty (s))
+    y = s;
+    return;
+  endif
+
+  ## Apparently, Matlab considers nulls to be blanks as well; however, does
+  ## not preserve the nulls, but rather converts them to blanks.  That's a
+  ## bit unexpected, but it allows simpler processing, because we can move
+  ## just the nonblank characters. So we'll do the same here.
+
+  [nr, nc] = size (s);
+  ## Find the indices of all nonblanks.
+  nonbl = s != " " & s != "\0";
+  [idx, jdx] = find (nonbl);
+
+  if (strcmpi (pos, "right"))
+    ## We wish to find the maximum column index for each row. Because jdx is
+    ## sorted, we can take advantage of the fact that assignment is processed
+    ## sequentially and for duplicate indices the last value will remain.
+    maxs = repmat (nc, [nr, 1]);
+    maxs(idx) = jdx;
+    shift = nc - maxs;
+  elseif (strcmpi (pos, "left"))
+    ## See above for explanation.
+    mins = ones (nr, 1);
+    mins(flipud (idx(:))) = flipud (jdx(:));
+    shift = 1 - mins;
+  else
+    ## Use both of the above to achieve centering.
+    mins = ones (nr, 1);
+    mins(flipud (idx(:))) = flipud (jdx(:));
+    maxs = repmat (nc, [nr, 1]);
+    maxs(idx) = jdx;
+    shift = floor ((nc + 1 - maxs - mins) / 2);
+  endif
+
+  ## Adjust the column indices.
+  jdx += shift(idx);
+
+  ## Create a blank matrix and position the nonblank characters.
+  y = repmat (" ", nr, nc);
+  y(sub2ind ([nr, nc], idx, jdx)) = s(nonbl);
+
+endfunction
+
+
+%!assert (strjust (["a"; "ab"; "abc"; "abcd"]),
+%!        ["   a";"  ab"; " abc"; "abcd"]);
+%!assert (strjust ([" a"; "  ab"; "abc"; "abcd"], "left"),
+%!        ["a   "; "ab  "; "abc "; "abcd"]);
+%!assert (strjust (["a"; "ab"; "abc"; "abcd"], "CENTER"),
+%!        [" a  "; " ab"; "abc "; "abcd"]);
+%!assert (strjust (["";""]), "");
+
+%% Test input validation
+%!error <Invalid call to strjust> strjust ()
+%!error <Invalid call to strjust> strjust (["a";"ab"], "center", 1)
+%!error <S must be a string> strjust (ones(3,3))
+%!error <S must be a string> strjust (char (ones(3,3,3)))
+