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author Daniel Wolff
date Fri, 19 Aug 2016 13:07:06 +0200
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Daniel@0 1 <html>
Daniel@0 2 <head>
Daniel@0 3 <title>
Daniel@0 4 Netlab Reference Manual pca
Daniel@0 5 </title>
Daniel@0 6 </head>
Daniel@0 7 <body>
Daniel@0 8 <H1> pca
Daniel@0 9 </H1>
Daniel@0 10 <h2>
Daniel@0 11 Purpose
Daniel@0 12 </h2>
Daniel@0 13 Principal Components Analysis
Daniel@0 14
Daniel@0 15 <p><h2>
Daniel@0 16 Synopsis
Daniel@0 17 </h2>
Daniel@0 18 <PRE>
Daniel@0 19 PCcoeff = pca(data)
Daniel@0 20 PCcoeff = pca(data, N)
Daniel@0 21 [PCcoeff, PCvec] = pca(data)
Daniel@0 22 </PRE>
Daniel@0 23
Daniel@0 24
Daniel@0 25 <p><h2>
Daniel@0 26 Description
Daniel@0 27 </h2>
Daniel@0 28
Daniel@0 29 <CODE>PCcoeff = pca(data)</CODE> computes the eigenvalues of the covariance
Daniel@0 30 matrix of the dataset <CODE>data</CODE> and returns them as <CODE>PCcoeff</CODE>. These
Daniel@0 31 coefficients give the variance of <CODE>data</CODE> along the corresponding
Daniel@0 32 principal components.
Daniel@0 33
Daniel@0 34 <p><CODE>PCcoeff = pca(data, N)</CODE> returns the largest <CODE>N</CODE> eigenvalues.
Daniel@0 35
Daniel@0 36 <p><CODE>[PCcoeff, PCvec] = pca(data)</CODE> returns the principal components as
Daniel@0 37 well as the coefficients. This is considerably more computationally
Daniel@0 38 demanding than just computing the eigenvalues.
Daniel@0 39
Daniel@0 40 <p><h2>
Daniel@0 41 See Also
Daniel@0 42 </h2>
Daniel@0 43 <CODE><a href="eigdec.htm">eigdec</a></CODE>, <CODE><a href="gtminit.htm">gtminit</a></CODE>, <CODE><a href="ppca.htm">ppca</a></CODE><hr>
Daniel@0 44 <b>Pages:</b>
Daniel@0 45 <a href="index.htm">Index</a>
Daniel@0 46 <hr>
Daniel@0 47 <p>Copyright (c) Ian T Nabney (1996-9)
Daniel@0 48
Daniel@0 49
Daniel@0 50 </body>
Daniel@0 51 </html>