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changeset 4679:c0302db81b75

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[project @ 2003-12-17 03:31:29 by jwe]
author jwe
date Wed, 17 Dec 2003 03:31:29 +0000
parents e1c2d8ca8bc0
children 493ff0643644
files scripts/general/ind2sub.m scripts/general/sub2ind.m
diffstat 2 files changed, 146 insertions(+), 0 deletions(-) [+]
line wrap: on
line diff
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/scripts/general/ind2sub.m	Wed Dec 17 03:31:29 2003 +0000
@@ -0,0 +1,75 @@
+## Copyright (C) 2001  Paul Kienzle <pkienzle@kienzle.powernet.co.uk>
+##
+## 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 -*-
+## @deftypefn {Function File} {[@var{s1}, @var{s2}, @dots{}, @var{sN}] =} sub2ind (@var{dims}, @var{ind})
+## Convert a linear index into subscripts.
+## @end deftypefn
+## @seealso{sub2ind}
+
+## Author: Paul Kienzle <pkienzle@kienzle.powernet.co.uk>
+## Adapted-by: jwe
+
+function varargout = ind2sub (dims, ind)
+
+  if (nargin == 2)
+    if (isvector (dims) && round (dims) == dims)
+      if (isnumeric (ind) && round (ind) == ind)
+	ntot = prod (dims);
+	if (ind > 0 & ind <= ntot)
+	  nd = length (dims);
+	  if (nargout > 0)
+	    vlen = nargout;
+	  else
+	    vlen = 1;
+	  endif
+	  if (nd > vlen);
+	    dims(vlen) = prod (dims(vlen:nd));
+	    dims(vlen+1:nd) = [];
+	  endif
+	  nd = length (dims);
+	  scale = [1; cumprod(dims(:))];
+	  for i = nd:-1:2
+	    k = (ind >= scale(i));
+	    r = ones (size (ind));
+	    t = zeros (size (ind));
+	    t(k) = floor ((ind(k) - 1) / scale(i));
+	    r(k) = t(k) + 1;
+	    varargout{i} = r;
+	    ind(k) -= t(k) * scale(i);
+	  endfor
+	  varargout{1} = ind;
+	  for i = nd+1:vlen
+	    varargout{i} = ones (size (ind));
+	  endfor
+	else
+	  error ("ind2sub: index out of range");
+	endif
+      else
+	error ("ind2sub: expecting integer-valued index argument");
+      endif
+    else
+      error ("sub2ind: expecting dims to be an integer vector");
+    endif
+  else
+    usage ("ind2sub (dims, ind)");
+  endif
+
+
+endfunction
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/scripts/general/sub2ind.m	Wed Dec 17 03:31:29 2003 +0000
@@ -0,0 +1,71 @@
+## Copyright (C) 2001  Paul Kienzle <pkienzle@kienzle.powernet.co.uk>
+##
+## 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 -*-
+## @deftypefn {Function File} {@var{ind} =} sub2ind (@var{dims}, @var{i}, @var{j})
+## @deftypefnx {Function File} {@var{ind} =} sub2ind (@var{dims}, @var{s1}, @var{s2}, @dots{}, @var{sN})
+## Convert subscripts into a linear index.
+## @end deftypefn
+## @seealso{ind2sub}
+
+## Author: Paul Kienzle <pkienzle@kienzle.powernet.co.uk>
+## Adapted-by: jwe
+
+function ind = sub2ind (dims, varargin)
+
+  if (nargin > 1)
+    if (isvector (dims) && round (dims) == dims)
+      nd = length (dims);
+      vlen = length (varargin);
+      dims(vlen) = prod (dims(vlen:nd));
+      dims(vlen+1:nd) = [];
+      scale = cumprod (dims(:));
+      for i = 1:vlen
+	arg = varargin{i};
+	if (isnumeric (arg) && round (arg) == arg)
+	  if (i == 1)
+	    if (arg > 0 & arg <= dims(i))
+	      ind = first_arg = arg;
+	    else
+	      error ("sub2ind: index out of range");
+	    endif
+	  else
+	    if (all (size (first_arg) == size (arg)))
+	      if ((i > nd && arg == 1) || (arg > 0 & arg <= dims(i)))
+		ind += scale(i-1) * (arg - 1);
+	      else
+		error ("sub2ind: index out of range");
+	      endif
+	    else
+	      error ("sub2ind: all index arguments must be the same size");
+	    endif
+	  endif
+	else
+	  error ("sub2ind: expecting integer-valued index arguments");
+	endif
+      endfor
+    else
+      error ("sub2ind: expecting dims to be an integer vector");
+    endif
+  else
+    usage ("sub2ind (dims, i1, i2, ..., iN)");
+  endif
+
+
+endfunction