Mercurial > hg > camir-aes2014
diff toolboxes/FullBNT-1.0.7/nethelp3.3/gmminit.htm @ 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/nethelp3.3/gmminit.htm Tue Feb 10 15:05:51 2015 +0000 @@ -0,0 +1,65 @@ +<html> +<head> +<title> +Netlab Reference Manual gmminit +</title> +</head> +<body> +<H1> gmminit +</H1> +<h2> +Purpose +</h2> +Initialises Gaussian mixture model from data + +<p><h2> +Synopsis +</h2> +<PRE> + +mix = gmminit(mix, x, options) +</PRE> + + +<p><h2> +Description +</h2> +<CODE>mix = gmminit(mix, x, options)</CODE> uses a dataset <CODE>x</CODE> +to initialise the parameters of a Gaussian mixture +model defined by the data structure <CODE>mix</CODE>. The k-means algorithm +is used to determine the centres. The priors are computed from the +proportion of examples belonging to each cluster. +The covariance matrices are calculated as the sample covariance of the +points associated with (i.e. closest to) the corresponding centres. +For a mixture of PPCA model, the PPCA decomposition is calculated +for the points closest to a given centre. +This initialisation can be used as the starting point for training the +model using the EM algorithm. + +<p><h2> +Example +</h2> +<PRE> + +mix = gmm(3, 2); +options = foptions; +options(14) = 5; +mix = gmminit(mix, data, options); +</PRE> + +This code sets up a Gaussian mixture model with 3 centres in 2 dimensions, and +then initialises the parameters from the data set <CODE>data</CODE> with 5 iterations +of the k means algorithm. + +<p><h2> +See Also +</h2> +<CODE><a href="gmm.htm">gmm</a></CODE><hr> +<b>Pages:</b> +<a href="index.htm">Index</a> +<hr> +<p>Copyright (c) Ian T Nabney (1996-9) + + +</body> +</html> \ No newline at end of file