--- a +++ b/ind2sub.m @@ -0,0 +1,47 @@ +## Copyright (C) 2001 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 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 + +## [ s1, s2, ...] = ind2sub (dims, ind) +## S = ind2sub (dims, ind) +## +## Convert a linear INDex into SUBscripts. If only one output argument +## is specified, then return a matrix, one column per subscript. +## +## See also: sub2ind + +## Author: Paul Kienzle <pkienzle@kienzle.powernet.co.uk> + +function [ ... ] = ind2sub (dims, ind) + + if ( nargin != 2 || all (nargout != [0, 1, length(dims)]) ) + usage ("[s1 s2 ...] = ind2sub (dims, ind) or S = ind2sub (dims, ind)"); + endif + + dims = dims(:); + n = length(dims); + power = ones (length(ind), 1) * cumprod ( [1, dims(1:n-1)'] ); + S = ind(:) * ones(1, n) - 1; + S = floor ( rem (S, dims(1)*power) ./ power ) + 1; + + if nargout <= 1 + vr_val(S); + else + for i=1:nargout + vr_val(S(:,i)); + endfor + endif + +endfunction