Re: [scikit-learn] Unclear help file about sklearn.decomposition.pca

2017-10-17 Thread Raphael C
How about including the scaling that people might want to use in the User Guide examples? Raphael On 17 October 2017 at 16:40, Andreas Mueller wrote: > In general scikit-learn avoids automatic preprocessing. > That's a convention to give the user more control and decrease surprising > behavior (

Re: [scikit-learn] Unclear help file about sklearn.decomposition.pca

2017-10-17 Thread Andreas Mueller
In general scikit-learn avoids automatic preprocessing. That's a convention to give the user more control and decrease surprising behavior (ostensibly). So scikit-learn will usually do what the algorithm is supposed to do, and nothing more. I'm not sure what the best way do document this is, a

[scikit-learn] Unclear help file about sklearn.decomposition.pca

2017-10-16 Thread Ismael Lemhadri
Thank you all for your feedback. The initial problem I came with wasnt the definition of PCA but what the sklearn method does. In practice I would always make sure the data is both centered and scaled before performing PCA. This is the recommended method because without scaling, the biggest directi