Mercurial > hg > camir-aes2014
diff toolboxes/FullBNT-1.0.7/netlab3.3/som.m @ 0:e9a9cd732c1e tip
first hg version after svn
author | wolffd |
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date | Tue, 10 Feb 2015 15:05:51 +0000 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/toolboxes/FullBNT-1.0.7/netlab3.3/som.m Tue Feb 10 15:05:51 2015 +0000 @@ -0,0 +1,55 @@ +function net = som(nin, map_size) +%SOM Creates a Self-Organising Map. +% +% Description +% NET = SOM(NIN, MAP_SIZE) creates a SOM NET with input dimension (i.e. +% data dimension) NIN and map dimensions MAP_SIZE. Only two- +% dimensional maps are currently implemented. +% +% The fields in NET are +% type = 'som' +% nin = number of inputs +% map_dim = dimension of map (constrained to be 2) +% map_size = grid size: number of nodes in each dimension +% num_nodes = number of nodes: the product of values in map_size +% map = map_dim+1 dimensional array containing nodes +% inode_dist = map of inter-node distances using Manhatten metric +% +% The map contains the node vectors arranged column-wise in the first +% dimension of the array. +% +% See also +% KMEANS, SOMFWD, SOMTRAIN +% + +% Copyright (c) Ian T Nabney (1996-2001) + +net.type = 'som'; +net.nin = nin; + +% Create Map of nodes +if round(map_size) ~= map_size | (map_size < 1) + error('SOM specification must contain positive integers'); +end + +net.map_dim = length(map_size); +if net.map_dim ~= 2 + error('SOM is a 2 dimensional map'); +end +net.num_nodes = prod(map_size); +% Centres are stored by column as first index of multi-dimensional array. +% This makes extracting them later more easy. +% Initialise with rand to create square grid +net.map = rand([nin, map_size]); +net.map_size = map_size; + +% Crude function to compute inter-node distances +net.inode_dist = zeros([map_size, net.num_nodes]); +for m = 1:net.num_nodes + node_loc = [1+fix((m-1)/map_size(2)), 1+rem((m-1),map_size(2))]; + for k = 1:map_size(1) + for l = 1:map_size(2) + net.inode_dist(k, l, m) = round(max(abs([k l] - node_loc))); + end + end +end