diff toolboxes/MIRtoolbox1.3.2/somtoolbox/som_connection.m @ 0:e9a9cd732c1e tip

first hg version after svn

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolboxes/MIRtoolbox1.3.2/somtoolbox/som_connection.m	Tue Feb 10 15:05:51 2015 +0000
@@ -0,0 +1,173 @@
+function C=som_connection(S)
+
+%SOM_CONNECTION Connection matrix for 'hexa' and 'rect' lattices
+%
+% C=som_connection(S)
+%
+%  C=som_connection(sMap);
+%  C=som_connection(sTopol);
+%  C=som_connection({'hexa', [6 5], 'sheet'});
+%
+% Input and output arguments:
+%  S    (struct) map or topol struct
+%       (cell array) a cell array of form {lattice, msize, shape}, where
+%                lattice: 'hexa' or 'rect'
+%                msize  : 1x2 vector
+%                shape  : 'sheet', 'cyl or 'toroid' 
+%
+%  C    (sparse) An NxN connection matrix, N=prod(msize)
+%
+% The function returns a connection matrix, e.g., for drawing
+% connections between map units in the function som_grid. Note that
+% the connections are defined only in the upper triangular part to
+% save some memory!! Function SOM_UNIT_NEIGHS does the same thing, 
+% but also has values in the lower triangular. It is also slower.
+%
+% For more help, try 'type som_connection' or check out online documentation.
+% See also SOM_GRID, SOM_UNIT_NEIGHS.
+
+%%%%%%%%%%%%% DETAILED DESCRIPTION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%
+% som_connection
+%
+% PURPOSE
+% 
+%  To create a connection matrix of SOM 'hexa' and 'rect' negihborhoods
+%
+% SYNTAX
+%
+%  C = som_connection(S)
+%
+% DESCRIPTION
+%
+%  Creates a connection matrix of SOM 'hexa' and 'rect'
+%  neighborhoods. The connections are defined only in the upper
+%  triangular part to save some memory.
+%  
+%  Function SOM_UNIT_NEIGHS does the same thing, but also has values
+%  in the lower triangular. It is also slower, except for 
+%  'toroid' shape because in that case this function calls 
+%  SOM_UNIT_NEIGHS...
+%
+% REQUIRED INPUT ARGUMENTS
+%  
+%  S                 map topology 
+%    (map struct)    S.topol is used to build the matrix
+%    (topol struct)  topology information is used to build the matrix
+%    (cell array)    of form {lattice, msize, shape}, where
+%                     lattice: 'hexa' or 'rect'
+%                     msize  : 1x2 vector
+%                     shape  : 'sheet', 'cyl or 'toroid' 
+%
+% OUTPUT ARGUMENTS
+%
+%  C (sparse)        munits x munits sparse matrix which describes 
+%                    nearest neighbor connections between units
+%
+% EXAMPLE 
+%
+% C = som_connection('hexa',[3 4],'sheet');
+% full(C)
+% ans =
+%
+%      0     1     0     1     0     0     0     0     0     0     0     0
+%      0     0     1     1     1     1     0     0     0     0     0     0
+%      0     0     0     0     0     1     0     0     0     0     0     0
+%      0     0     0     0     1     0     1     0     0     0     0     0
+%      0     0     0     0     0     1     1     1     1     0     0     0
+%      0     0     0     0     0     0     0     0     1     0     0     0
+%      0     0     0     0     0     0     0     1     0     1     0     0
+%      0     0     0     0     0     0     0     0     1     1     1     1
+%      0     0     0     0     0     0     0     0     0     0     0     1
+%      0     0     0     0     0     0     0     0     0     0     1     0
+%      0     0     0     0     0     0     0     0     0     0     0     1
+%      0     0     0     0     0     0     0     0     0     0     0     0
+%
+% SEE ALSO
+% 
+% som_grid         Visualization of a SOM grid
+% som_unit_neighs  Units in 1-neighborhood for all map units.
+
+% Copyright (c) 1999-2000 by the SOM toolbox programming team.
+% http://www.cis.hut.fi/projects/somtoolbox/             
+
+% Version 2.0alpha Johan 061099 juuso 151199 170400
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% Check arguments
+
+error(nargchk(1, 1, nargin));   % check number of input arguments
+
+[tmp,ok,tmp]=som_set(S);
+if isstruct(S) & all(ok),       % check m type
+  switch S.type
+  case 'som_topol' 
+    msize=S.msize;
+    lattice=S.lattice;
+    shape=S.shape;
+  case 'som_map'  
+    msize=S.topol.msize;
+    lattice=S.topol.lattice;
+    shape=S.topol.shape;
+  otherwise
+    error('Invalid map or topol struct.');
+  end
+elseif iscell(S),
+  if vis_valuetype(S,{'topol_cell'}),
+    lattice=S{1};
+    msize=S{2}; 
+    shape=S{3}; 
+  else
+    error('{lattice, msize, shape} expected for cell input.')
+  end
+else
+  error('{lattice, msize, shape}, or map or topol struct expected.')
+end
+
+if ~vis_valuetype(msize,{'1x2'})
+  error('Invalid map size: only 2D maps allowed.')
+end  
+
+%% Init %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+N=msize(1)*msize(2);
+
+%% Action & Build output arguments %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+switch lattice
+case 'hexa'
+  l1=ones(N,1); l1((msize(1)+1):msize(1):end)=0;
+  l2=zeros(msize(1),1); l3=l2;
+  l2(1:2:end-1)=1; l3(3:2:end)=1;
+  l2=repmat(l2,msize(2),1); 
+  l3=repmat(l3,msize(2),1);
+  C= ...
+    spdiags([l1 l2 ones(N,1) l3], [1 msize(1)-1:msize(1)+1],N,N);
+case 'rect'
+  l1=ones(N,1);l1((msize(1)+1):msize(1):end)=0;
+  C=spdiags([l1 ones(N,1)],[1 msize(1)],N,N);
+otherwise
+  error('Unknown lattice.')
+end
+
+switch shape
+case 'sheet'
+  ;
+case 'cyl'
+  C=spdiags(ones(N,1),msize(1)*(msize(2)-1),C);
+case 'toroid'
+  %warning('Toroid not yet implemented: using ''cyl''.');
+  %C=spdiags(ones(N,1),msize(1)*(msize(2)-1),C);
+  %l=zeros(N,1); l(1:msize(2):end)=1;
+  %C=spdiags(l,msize(1),C);
+
+  % use som_unit_neighs to calculate these
+  C = som_unit_neighs(msize,lattice,'toroid');
+  % to be consistent, set the lower triangular values to zero
+  munits = prod(msize);
+  for i=1:(munits-1), C((i+1):munits,i) = 0; end
+otherwise
+  error('Unknown shape.');
+end
+
+