Mercurial > hg > camir-aes2014

comparison toolboxes/FullBNT-1.0.7/nethelp3.3/nethess.htm @ 0:e9a9cd732c1e tip

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
first hg version after svn
author wolffd
date Tue, 10 Feb 2015 15:05:51 +0000
parents
children
comparison
equal deleted inserted replaced
-1:000000000000 0:e9a9cd732c1e
1 <html>
2 <head>
3 <title>
4 Netlab Reference Manual nethess
5 </title>
6 </head>
7 <body>
8 <H1> nethess
9 </H1>
10 <h2>
11 Purpose
12 </h2>
13 Evaluate network Hessian
14
15 <p><h2>
16 Synopsis
17 </h2>
18 <PRE>
19 h = neterr(w, net, x, t)
20 [h, varargout] = neterr(w, net, x, t, varargin)
21 </PRE>
22
23
24 <p><h2>
25 Description
26 </h2>
27
28 <p><CODE>h = nethess(w, net, x, t)</CODE> takes a weight vector <CODE>w</CODE> and a network
29 data structure <CODE>net</CODE>, together with the matrix <CODE>x</CODE> of input
30 vectors and the matrix <CODE>t</CODE> of target vectors, and returns the
31 value of the Hessian evaluated at <CODE>w</CODE>.
32
33 <p><CODE>[e, varargout] = nethess(w, net, x, t, varargin)</CODE> also returns any additional
34 return values from the network Hessian function, and passes additional arguments
35 to that function.
36
37 <p><h2>
38 Example
39 </h2>
40
41 <p>In <CODE>evidence</CODE>, this function is called once to compute the
42 data contribution to the Hessian
43 <PRE>
44
45 [h, dh] = nethess(w, net, x, t, dh);
46 </PRE>
47
48 and again to update the Hessian for new values of the hyper-parameters
49 <PRE>
50
51 h = nethess(w, net, x, t, dh);
52 </PRE>
53
54
55 <p><h2>
56 See Also
57 </h2>
58 <CODE><a href="neterr.htm">neterr</a></CODE>, <CODE><a href="netgrad.htm">netgrad</a></CODE>, <CODE><a href="netopt.htm">netopt</a></CODE><hr>
59 <b>Pages:</b>
60 <a href="index.htm">Index</a>
61 <hr>
62 <p>Copyright (c) Ian T Nabney (1996-9)
63
64
65 </body>
66 </html>