comparison toolboxes/FullBNT-1.0.7/netlab3.3/somfwd.m @ 0:e9a9cd732c1e tip

first hg version after svn

+function [d2, win_nodes] = somfwd(net, x)
+%SOMFWD	Forward propagation through a Self-Organising Map.
+%
+%	Description
+%	D2 = SOMFWD(NET, X) propagates the data matrix X through  a SOM NET,
+%	returning the squared distance matrix D2 with dimension NIN by
+%	NUM_NODES.  The $i$th row represents the squared Euclidean distance
+%	to each of the nodes of the SOM.
+%
+%	[D2, WIN_NODES] = SOMFWD(NET, X) also returns the indices of the
+%	winning nodes for each pattern.
+%
+%	See also
+%	SOM, SOMTRAIN
+%
+
+%	Copyright (c) Ian T Nabney (1996-2001)
+
+% Check for consistency
+errstring = consist(net, 'som', x);
+if ~isempty(errstring)
+    error(errstring);
+end
+
+% Turn nodes into matrix of centres
+nodes = (reshape(net.map, net.nin, net.num_nodes))';
+% Compute squared distance matrix
+d2 = dist2(x, nodes);
+% Find winning node for each pattern: minimum value in each row
+[w, win_nodes] = min(d2, [], 2);