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

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* [[...find outliers]]
 
* [[...find outliers]]
 
* [[Clustering]]
 
* [[Clustering]]
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* [[Manifold Hypothesis]]
 
* [[Anomaly Detection]]
 
* [[Anomaly Detection]]
 
* [[Dimensional Reduction]]
 
* [[Dimensional Reduction]]

Revision as of 09:12, 3 September 2020

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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


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