Difference between revisions of "Principal Component Analysis (PCA)"

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* [[T-Distributed Stochastic Neighbor Embedding (t-SNE)]]
 
* [[T-Distributed Stochastic Neighbor Embedding (t-SNE)]]
 
* [http://www.cs.helsinki.fi/u/ahyvarin/whatisica.shtml Independent Component Analysis (ICA) | University of Helsinki]
 
* [http://www.cs.helsinki.fi/u/ahyvarin/whatisica.shtml Independent Component Analysis (ICA) | University of Helsinki]
 +
** [http://www.cs.helsinki.fi/u/ahyvarin/papers/JMLR06.pdf Linear Non-Gaussian Acyclic Model (ICA-LiNGAM)] | S. Shimizu, P. Hoyer, A. Hyvarinen, and A. Kerminen - University of Helsinki]
  
 
a data reduction technique that allows to simplify multidimensional data sets to 2 or 3 dimensions for plotting purposes and visual variance analysis.
 
a data reduction technique that allows to simplify multidimensional data sets to 2 or 3 dimensions for plotting purposes and visual variance analysis.

Revision as of 10:41, 22 June 2019

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a data reduction technique that allows to simplify multidimensional data sets to 2 or 3 dimensions for plotting purposes and visual variance analysis.

  1. Center (and standardize) data
  2. First principal component axis
    1. Across centroid of data cloud
    2. Distance of each point to that line is minimized, so that it crosses the maximum variation of the data cloud
  3. Second principal component axis
    1. Orthogonal to first principal component
    2. Along maximum variation in the data
  4. First PCA axis becomes x-axis and second PCA axis y-axis
  5. Continue process until the necessary number of principal components is obtained


principal-component-analysis-basics-scatter-plot-data-mining-1.png


NumXL