comparison toolboxes/FullBNT-1.0.7/bnt/potentials/@scgpot/reduce_pot.m @ 0:e9a9cd732c1e tip

first hg version after svn

+function [reduced_pot,successful] = reduce_pot(pot,tailnodes)
+% Executes the reduce operation defined in
+% Stable Local Computation with Conditional Gaussian Distributions
+% Steffen L. Lauritzen
+% Frank Jensen
+% September 1999
+% The potential pot is reduced if B contains any zero columns
+% The test are restricted to the positions in tailnodes.
+% Any columns successfully deleted are entered in the array successful
+if nargin < 2
+    tailnodes = pot.ctaildom;
+end
+
+successful = [];
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% Keep track of remaining tailnodes %
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+rem_tailnodes = pot.ctaildom;
+for i = tailnodes
+    pos = find(i==rem_tailnodes);
+    successful_red = [pos];
+    red_scgcpot = cell(1,pot.dsize);
+    j = 1;
+    %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+    % Test whether all components of pot.scgpotc can be reduced %
+    %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+    while ((j <= pot.dsize) & ~isempty(successful_red))
+        [cpot,successful_red] = reduce_pot(pot.scgpotc{j},pos);
+        red_scgcpot{j} = cpot;
+        j = j + 1;
+    end
+
+    %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+    % If i is a reducible tailnode, then reduce the potential %
+    %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+    if ~isempty(successful_red)
+        successful = [successful i];
+        pot.scgpotc = red_scgcpot;
+        rem_tailnodes = mysetdiff(rem_tailnodes,i);
+    end;
+end
+
+pot.ctaildom = rem_tailnodes;
+positions = find_equiv_posns(rem_tailnodes,pot.ctaildom);
+pot.ctailsizes = pot.ctailsizes(positions);
+pot.ctailsize = sum(pot.ctailsizes);
+pot.domain = mysetdiff(pot.domain,successful);
+reduced_pot = pot;
+
+
+
+
+