2012/9/4 <[email protected]>: > Date: Tue, 04 Sep 2012 14:49:44 +0100 > From: Andreas Mueller <[email protected]> > Subject: [Scikit-learn-general] p values of exactly zero in chi2 > To: [email protected] > Message-ID: <[email protected]> > Content-Type: text/plain; charset=ISO-8859-1; format=flowed > > Hi everybody. > I'm pretty new to feature selection stuff and I tried to use the chi2 > selection. > I got a pvalue of exactly zero on one of the features and one of e-250 > on another one. > That seems a bit fishy, in particular as they don't seem to correlate > very strongly. > Maybe I misunderstood something. > Any hints?
What did the input look like? chi2 expects frequencies, i.e. strictly non-negative feature values. -- Lars Buitinck Scientific programmer, ILPS University of Amsterdam ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Scikit-learn-general mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/scikit-learn-general
