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wolffd@0 1 <html>
wolffd@0 2 <head>
wolffd@0 3 <title>
wolffd@0 4 Netlab Reference Manual rbffwd
wolffd@0 5 </title>
wolffd@0 6 </head>
wolffd@0 7 <body>
wolffd@0 8 <H1> rbffwd
wolffd@0 9 </H1>
wolffd@0 10 <h2>
wolffd@0 11 Purpose
wolffd@0 12 </h2>
wolffd@0 13 Forward propagation through RBF network with linear outputs.
wolffd@0 14
wolffd@0 15 <p><h2>
wolffd@0 16 Synopsis
wolffd@0 17 </h2>
wolffd@0 18 <PRE>
wolffd@0 19 a = rbffwd(net, x)
wolffd@0 20 function [a, z, n2] = rbffwd(net, x)
wolffd@0 21 </PRE>
wolffd@0 22
wolffd@0 23
wolffd@0 24 <p><h2>
wolffd@0 25 Description
wolffd@0 26 </h2>
wolffd@0 27 <CODE>a = rbffwd(net, x)</CODE> takes a network data structure
wolffd@0 28 <CODE>net</CODE> and a matrix <CODE>x</CODE> of input
wolffd@0 29 vectors and forward propagates the inputs through the network to generate
wolffd@0 30 a matrix <CODE>a</CODE> of output vectors. Each row of <CODE>x</CODE> corresponds to one
wolffd@0 31 input vector and each row of <CODE>a</CODE> contains the corresponding output vector.
wolffd@0 32 The activation function that is used is determined by <CODE>net.actfn</CODE>.
wolffd@0 33
wolffd@0 34 <p><CODE>[a, z, n2] = rbffwd(net, x)</CODE> also generates a matrix <CODE>z</CODE> of
wolffd@0 35 the hidden unit activations where each row corresponds to one pattern.
wolffd@0 36 These hidden unit activations represent the <CODE>design matrix</CODE> for
wolffd@0 37 the RBF. The matrix <CODE>n2</CODE> is the squared distances between each
wolffd@0 38 basis function centre and each pattern in which each row corresponds
wolffd@0 39 to a data point.
wolffd@0 40
wolffd@0 41 <p><h2>
wolffd@0 42 Examples
wolffd@0 43 </h2>
wolffd@0 44 <PRE>
wolffd@0 45
wolffd@0 46 [a, z] = rbffwd(net, x);
wolffd@0 47
wolffd@0 48 <p>temp = pinv([z ones(size(x, 1), 1)]) * t;
wolffd@0 49 net.w2 = temp(1: nd(2), :);
wolffd@0 50 net.b2 = temp(size(x, nd(2)) + 1, :);
wolffd@0 51 </PRE>
wolffd@0 52
wolffd@0 53 Here <CODE>x</CODE> is the input data, <CODE>t</CODE> are the target values, and we use the
wolffd@0 54 pseudo-inverse to find the output weights and biases.
wolffd@0 55
wolffd@0 56 <p><h2>
wolffd@0 57 See Also
wolffd@0 58 </h2>
wolffd@0 59 <CODE><a href="rbf.htm">rbf</a></CODE>, <CODE><a href="rbferr.htm">rbferr</a></CODE>, <CODE><a href="rbfgrad.htm">rbfgrad</a></CODE>, <CODE><a href="rbfpak.htm">rbfpak</a></CODE>, <CODE><a href="rbftrain.htm">rbftrain</a></CODE>, <CODE><a href="rbfunpak.htm">rbfunpak</a></CODE><hr>
wolffd@0 60 <b>Pages:</b>
wolffd@0 61 <a href="index.htm">Index</a>
wolffd@0 62 <hr>
wolffd@0 63 <p>Copyright (c) Ian T Nabney (1996-9)
wolffd@0 64
wolffd@0 65
wolffd@0 66 </body>
wolffd@0 67 </html>