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Function for principal component analysis (PCA)?

Tsai Ming-Chou

Tsai Ming-Chou, National Defense Medical Center

Posted 5 years ago

I downloaded the Boston housing price data collection from the Internet for practice. Related blogs discuss principal component analysis (PCA). But I did not search for relevant examples, commands, or functions on the Wolfram website. Are there any readily commands or functions for PCA in Mathematica? Remove["Global`*"] {key, data} = {First@#, 0.0 + ToExpression@Rest@#} &@ Import["https://raw.githubusercontent.com/selva86/datasets/master/\ BostonHousing.csv", {"CSV", "RawData"}]; {test, train} = TakeDrop[#, 100] &@((#[[1 ;; -2]] -> #[[-1]]) & /@ data); p = Predict[train]; m = PredictorMeasurements[p1, test]; m["Properties"]

I downloaded the Boston housing price data collection from the Internet for practice. Related blogs discuss principal component analysis (PCA). But I did not search for relevant examples, commands, or functions on the Wolfram website. Are there any readily commands or functions for PCA in Mathematica?

Remove["Global`*"]
{key, data} = {First@#, 0.0 + ToExpression@Rest@#} &@
   Import["https://raw.githubusercontent.com/selva86/datasets/master/\
BostonHousing.csv", {"CSV", "RawData"}];
{test, train} = 
  TakeDrop[#, 100] &@((#[[1 ;; -2]] -> #[[-1]]) & /@ data);
p = Predict[train];
m = PredictorMeasurements[p1, test];
m["Properties"]

POSTED BY: Tsai Ming-Chou

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Rohit Namjoshi

Posted 5 years ago

Hi Ming-Chou, WL has a `PrincipalComponents` function that may work for you. A suggestion on your code. Evaluating `ToExpression` on data from an external source can pose a security risk. Here is an alternative dataset = Import["https://raw.githubusercontent.com/selva86/datasets/master/BostonHousing.csv", "Dataset", HeaderLines -> 1]; dataPredict = dataset[All, Most@Values@# -> Last@Values@# &] // Normal It is important to randomize the data before analyzing it to remove any bias from the way the data is sorted. The `ResourceFunction` `TrainTestSplit` is useful for this. {train, test} = ResourceFunction["TrainTestSplit"][dataPredict]; p = Predict[train]; There is a typo in the code, `p` should be passed to `PredictorMeasurements`, not `p1`.