Hi, Thanks a lot for your comments. I did try earlier on to remove the bad points but came across some problems when re-ordering my array. I will try out the method sent to me and check the reference.
Regards, Marjolaine. >>> <kgdunn+nab...@gmail.com> 02/11/09 4:06 PM >>> Marjolaine, I am assuming your masked array entries are missing data. Multivariate analysis with missing data can be handled in several standard ways, however these methods don't appear in most Python libraries. Here are some references on the topic that will help you: [1] P.R.C. Nelson and J.F. MacGregor, 1996, "Missing data methods in PCA and PLS: Score calculations with incomplete observations", Chemometrics and Intelligent Laboratory Systems, v35, p 45-65. [2] F. Arteaga and A. Ferrer, 2002, "Dealing with missing data in MSPC: several methods, different interpretations, some examples", Journal of Chemometrics, v16, p408-418. Paper [1] deals with building a model with missing data, while paper [2] looks at applying an existing PCA model to new data that contains missing entries. Hope these help, Kevin Marjolaine Rouault wrote: > > Hi, > > I am struggling to do a PCA analysis on a masked array. Anybody has > suggestions on how to deal with masked array when doing PCAs? > > Best regards, Marjolaine. > Quoted from: http://www.nabble.com/matplotlib.mlab-PCA-analysis-tp21932808p21932808.html -- This message is subject to the CSIR's copyright terms and conditions, e-mail legal notice, and implemented Open Document Format (ODF) standard. The full disclaimer details can be found at http://www.csir.co.za/disclaimer.html. This message has been scanned for viruses and dangerous content by MailScanner, and is believed to be clean. MailScanner thanks Transtec Computers for their support. ------------------------------------------------------------------------------ Create and Deploy Rich Internet Apps outside the browser with Adobe(R)AIR(TM) software. With Adobe AIR, Ajax developers can use existing skills and code to build responsive, highly engaging applications that combine the power of local resources and data with the reach of the web. Download the Adobe AIR SDK and Ajax docs to start building applications today-http://p.sf.net/sfu/adobe-com _______________________________________________ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
