vec2mat.m

## Copyright (C) 2001 Laurent Mazet
##
## 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; if not, see <http://www.gnu.org/licenses/>.

## -*- texinfo -*-
## @deftypefn  {Function File} {@var{m} =} vec2mat (@var{v}, @var{c})
## @deftypefnx {Function File} {@var{m} =} vec2mat (@var{v}, @var{c}, @var{d})
## @deftypefnx {Function File} {[@var{m}, @var{add}] =} vec2mat (@dots{})
##
## Converts the vector @var{v} into a @var{c} column matrix with row priority
## arrangement and with the final column padded with the value @var{d} to the
## correct length. By default @var{d} is 0. The amount of padding added to
## the matrix is returned in @var{add}.
## @end deftypefn

function [M, d] = vec2mat (V, c, val)

  switch (nargin)
    case 1
      M = V;
      return;
    case 2
      val = 0;
    case 3
      val = val;
    otherwise
      print_usage ();
  endswitch

  V = V.';
  V = V(:);

  r = ceil (length (V) / c);

  d = r * c - length (V);
  if (d != 0)
    V = [V; val*ones(d, 1)];
  endif

  M = reshape (V, c, r).';

endfunction

%!assert (vec2mat ([]), [])
%!assert (vec2mat (1), 1)
%!assert (vec2mat (1, 5), [1 0 0 0 0])
%!assert (vec2mat (0:8), 0:8)
%!assert (vec2mat (0:8, 3), [0:2; 3:5; 6:8])

%% Test input validation
%!error vec2mat ()
%!error vec2mat (1, 2, 3, 4)