comparison toolboxes/FullBNT-1.0.7/graph/mk_nbrs_of_dag.m @ 0:e9a9cd732c1e tip

first hg version after svn

+function [Gs, op, nodes] = mk_nbrs_of_dag(G0)
+% MK_NBRS_OF_DAG Make all DAGs that differ from G0 by a single edge deletion, addition or reversal
+% [Gs, op, nodes] = mk_nbrs_of_dag(G0)
+%
+% Gs{i} is the i'th neighbor.
+% op{i} = 'add', 'del', or 'rev' is the operation used to create the i'th neighbor.
+% nodes(i,1:2) are the head and tail of the operated-on arc.
+
+Gs = {};
+op = {};
+nodes = [];
+
+[I,J] = find(G0);
+nnbrs = 1;
+% all single edge deletions
+for e=1:length(I)
+  i = I(e); j = J(e);
+  G = G0;
+  G(i,j) = 0;
+  Gs{nnbrs} = G;
+  op{nnbrs} = 'del';
+  nodes(nnbrs, :) = [i j];
+  nnbrs = nnbrs + 1;
+end
+
+% all single edge reversals
+for e=1:length(I)
+  i = I(e); j = J(e);
+  G = G0;
+  G(i,j) = 0;
+  G(j,i) = 1;
+  if acyclic(G)
+    Gs{nnbrs} = G;
+    op{nnbrs} = 'rev';
+    nodes(nnbrs, :) = [i j];
+    nnbrs = nnbrs + 1;
+  end
+end
+
+[I,J] = find(~G0);
+% all single edge additions
+for e=1:length(I)
+  i = I(e); j = J(e);
+  if i ~= j % don't add self arcs
+    G = G0;
+    G(i,j) = 1;
+    if G(j,i)==0 % don't add i->j if j->i exists already
+      if acyclic(G)
+	Gs{nnbrs} = G;
+	op{nnbrs} = 'add';
+	nodes(nnbrs, :) = [i j];
+	nnbrs = nnbrs + 1;
+      end
+    end
+  end
+end
+
+
+
+
+
+
+
+