--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/m-toolbox/classes/@ssm/blockMatIndex.m	Wed Nov 23 19:22:13 2011 +0100
@@ -0,0 +1,61 @@
+% adds corresponding matrices of same sizes or empty inside cell array
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%
+% DESCRIPTION: blockMatAdd adds corresponding matrices of same sizes or empty inside
+% cell array
+%
+% CALL: [cell3] = ssm.blockMatAdd(cell1,cell2)
+%
+% INPUTS:
+%       cell1 - cell array of matrices representing a matrix by blocs.
+%               blocs may be empty
+%       cell2 - cell array of matrices representing a matrix by blocs.
+%               blocs may be empty
+%
+% OUTPUTS:
+%       cell3 - cell array of matrices representing a matrix by blocs.
+%               blocs may be empty
+%
+% NOTE : function is private to the ssm class
+%
+% VERSION: '$Id: blockMatIndex.m,v 1.8 2011/02/02 19:25:30 adrien Exp $'
+%
+% TO DO :
+% check ME in case of mixed symbolic and double
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+function a = blockMatIndex(amats, blockIndex1, portIndex1, blockIndex2, portIndex2 )
+  %% filling binary array to check is location is empty
+  isEmpty = cellfun(@isempty, amats);
+ 
+  Nrow = size(amats,1);
+  Ncol = size(amats,2);
+
+  n1 = numel(blockIndex1);
+  n2 = numel(blockIndex2);
+  a = zeros(n1, n2);
+
+  %% rebuilding input indexing vector
+  [groupedBlockIndex1, groupedPortIndex1, groupSize1, nGroups1, globalPortIndex1] = ssmblock.groupIndexes(blockIndex1, portIndex1);
+  [groupedBlockIndex2, groupedPortIndex2, groupSize2, nGroups2, globalPortIndex2] = ssmblock.groupIndexes(blockIndex2, portIndex2);
+  %% Copying content
+  for ii=1:nGroups1
+    bi = groupedBlockIndex1(ii);
+    pi = groupedPortIndex1{ii};
+    for jj=1:nGroups2
+      bj = groupedBlockIndex2(jj);
+      if ~isEmpty(bi, bj) || min(bi,Nrow)==min(bj,Ncol)
+        % if we have a non-empty cell or we are on the extended diagonal
+        val = amats{bi, bj}(pi,groupedPortIndex2{jj});
+        if isa(val, 'sym') && ~isa(a, 'sym')
+          a = sym(a);
+        end
+        a(globalPortIndex1{ii},globalPortIndex2{jj}) = val;
+
+      end
+    end
+  end
+  
+end
+
+
+