Contiguous

Contiguous - Determine a patch of contiguous points.

  Given a matrix of zeros and ones, where ones form 'patches' of contiguous
  items, find all items that belong to the same patch as item (i,j).

  USAGE

    y = Contiguous(x,i,j)

    x              input matrix
    i,j            starting coordinates (row first)

  OUTPUT

    Y              output matrix, where for all k and l
                    * y(k,l) = 0 if x(k,l) = 0
                    * y(k,l) = 1 if x(k,l) = 1 but (k,l) is not in the same
                      patch as (i,j)
                    * y(k,l) = 2 if x(k,l) = 1 and (k,l) is in the same patch
                      as (i,j)

0001 %Contiguous - Determine a patch of contiguous points.
0002 %
0003 %  Given a matrix of zeros and ones, where ones form 'patches' of contiguous
0004 %  items, find all items that belong to the same patch as item (i,j).
0005 %
0006 %  USAGE
0007 %
0008 %    y = Contiguous(x,i,j)
0009 %
0010 %    x              input matrix
0011 %    i,j            starting coordinates (row first)
0012 %
0013 %  OUTPUT
0014 %
0015 %    Y              output matrix, where for all k and l
0016 %                    * y(k,l) = 0 if x(k,l) = 0
0017 %                    * y(k,l) = 1 if x(k,l) = 1 but (k,l) is not in the same
0018 %                      patch as (i,j)
0019 %                    * y(k,l) = 2 if x(k,l) = 1 and (k,l) is in the same patch
0020 %                      as (i,j)
0021 
0022 % Copyright (C) 2013 by Michaël Zugaro
0023 %
0024 % This program is free software; you can redistribute it and/or modify
0025 % it under the terms of the GNU General Public License as published by
0026 % the Free Software Foundation; either version 3 of the License, or
0027 % (at your option) any later version.