From bug-request at octave dot org Thu Feb  3 08:12:28 2005
Subject: dec2base.m bug
From: "Bruce Puckett" <bpuckett at iomax dot net>
To: <bug at octave dot org>
Date: Thu, 3 Feb 2005 07:17:47 -0600

In dec2base, if you have specified the length, why would you remove leading
zeros.  If you're specifying a particular length, you probably want the
zeros.  I've marked my changes on the left with " at "| instead of " instead of "|".  If you
make the change, give credit to Brian Donlan.

bp

|## Copyright (C) 2000 Daniel Calvelo
|##
|## 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, 59 Temple Place - Suite 330, Boston, MA
|## 02111-1307, USA.
|
|## -*- texinfo -*-
|##  at deftypefn {Function File} {} dec2base (@var{n}, @var{b}, @var{len})
|## Return a string of symbols in base  at var{b} corresponding to the
|## the nonnegative integer  at var{n} dot 
|##
|##  at example
|## dec2base (123, 3)
|##       at result{} "11120"
|##  at end example
|##
|## If  at var{n} is a vector, return a string matrix with one row per value,
|## padded with leading zeros to the width of the largest value.
|##
|## If  at var{b} is a string then the characters of @var{b} are used as
|## the symbols for the digits of  at var{n} dot   Space (' ') may not be used
|## as a symbol.
|##
|##  at example
|## dec2base (123, "aei")
|##       at result{} "eeeia"
|##  at end example
|##
|## The optional third argument,  at var{len}, specifies the minimum
|## number of digits in the result.
|##  at end deftypefn
|##
|##  at seealso{base2dec, dec2bin, bin2dec, hex2dec, dec2hex}
|
|## Author: Daniel Calvelo <dcalvelo at yahoo dot com>
|## Adapted-by: Paul Kienzle <pkienzle at kienzle dot powernet dot co dot uk>
|
|function retval = dec2base (n, base, len)
|
|  if (nargin < 2 || nargin > 3)
|    usage ("dec2base (n, base [, len])");
|  endif
|
|  if (prod (size (n)) != length (n))
|    error ("dec2base: cannot convert matrices.");
|  elseif (any (n < 0 | n != fix (n)))
|    error ("dec2base: can only convert non-negative integers.")
|  endif
|
|  symbols = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
|  if (isstr (base))
|    symbols = base;
|    base = length (symbols);
|    if any (diff (sort (toascii (symbols))) == 0)
|      error ("dec2base: symbols representing digits must be unique.");
|    endif
|  elseif (! isscalar (base))
|    error ("dec2base: cannot convert from several bases at once.");
|  elseif (base < 2 || base > length (symbols))
|    error ("dec2base: base must be between 2 and 36 or a string of
symbols");
|  endif
|
|  ## determine number of digits required to handle all numbers, can
overflow
|  max_n = max(max(n),1);
|  max_len = ceil(log(max_n)/log(base));
|  if (base^max_len <= max_n) max_len++; endif
|
|  if (nargin == 3)
|    max_len = max (max_len, len);
|  endif
|
|  ## determine digits for each number
|  power = ones (length (n), 1) * (base .^ (max_len-1 : -1 : 0));
|  n = n(:) * ones (1, max_len);
|  digits = floor (rem (n, base*power) ./ power);
|
|  ## convert digits to symbols
|  retval = reshape (symbols (digits+1), size (digits));
|
|  ## Check if the first element is the zero symbol
 at   if (nargin ~= 3)
|  if (all (retval(:,1) == symbols(1)))
|    retval = retval(:,2:end);
|  endif
 at   endif
|
|endfunction



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