## 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 2 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, write to the Free Software
## Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

## usage: b = de2bi(d, [n, [p]])
##
## Convert a non-negative integer to bit vector.
##
## d: positive integer
## n: number of rows of the ouput bit vector (default is max. size).
## p: base of decomposition (default is 2).
##
## b : bit vector.

## 2001-02-02
##   initial release

function b = de2bi(d, n, p)

  if (nargin == 1)
    p = 2;
    n = floor ( log (max (max (d), 1)) ./ log (p) ) + 1;
  elseif (nargin == 2)
    p = 2;
  elseif (nargin != 3)
    error ("usage: b = de2bi (d [, n [, p]])");
  endif

  d = d(:);
  if ( any (d < 0) || any (d != floor (d)) )
    error ("de2bi: only handles non-negative integers");
  endif

  power = ones (length (d), 1) * (p .^ [0 : n-1] );
  d = d * ones (1, n);
  b = floor (rem (d, p*power) ./ power);

endfunction