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  == Singular Value Decomposition <i>versus</i> Principal Component Analysis ==
 +  #REDIRECT [[Singular Value Decomposition <i>versus</i> Principal Component Analysis]] 
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  from <i>SVD meets PCA</i>, slide by Cleve Moler
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  “''The Wikipedia pages on SVD and PCA are quite good and contain a number of useful links, although not to each other.''”
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  <br>[https://www.mathworks.com/company/newsletters/articles/professorsvd.html <math></math>MATLAB News & Notes, Cleve’s Corner, 2006]
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  <pre>
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  %relationship of pca to svd
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  m=3; n=7;
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  A = randn(m,n);
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  [coef,score,latent] = pca(A)
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  X = A  mean(A);
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  [U,S,V] = svd(X,'econ');
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  % S vs. latent
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  rho = rank(X);
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  latent = diag(S(:,1:rho)).^2/(m1)
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  % U vs. score
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  sense = sign(score).*sign(U*S(:,1:rho)); %account for negated left singular vector
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  score = U*S(:,1:rho).*sense
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  % V vs. coef
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  sense2 = sign(coef).*sign(V(:,1:rho)); %account for corresponding negated right singular vector
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  coef = V(:,1:rho).*sense2
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  </pre>
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Revision as of 16:24, 12 September 2018
 REDIRECT [[Singular Value Decomposition versus Principal Component Analysis]]