Thanks to Mr.Liviu Androvic and Mr.Richard Rowe helped me in PCA. Because I have just learn R language in a few day so I have many problem. 1) I don't know why PCA rotation function not run although I try many times. Would you please hepl me and explain how to read the PCA map (both of rotated and unrotated) in a concrete example. 2) Where I can find document relate: Plan S(A), S(A*B), S(A)*B? Thanks alot. -- View this message in context: http://www.nabble.com/Principle-component-analysis-tp15846902p15846902.html Sent from the R help mailing list archive at Nabble.com.
phthao05 <phthao05 <at> gmail.com> writes: [snip]> Because I have just learn R language in a few day so I have many problem. > 1) I don't know why PCA rotation function not run although I try many times. > Would you please hepl me and explain how to read the PCA map (both of > rotated and unrotated) in a concrete example. > 2) Where I can find document relate: Plan S(A), S(A*B), S(A)*B? > Thanks alot.You haven't given us enough information to help you: please read the posting guide (referenced in every R-help posting). (1) you need to give _us_ a "concrete example" (not the other way around) that shows us what you tried, how far you got, and what "not run" means (see the posting guide for more information about asking questions on the list). (2) Can you clarify the question? I don't know what "Plan S(A), S(A*B), S(A)*B" means, at all ... Venables and Ripley's book is a terse, but useful, introduction to many topics in R. There are other books listed on the web page ... (and by the way, that's "principal" component analysis -- I wish I could ignore it but I can't) good luck, Ben Bolker
On 3/5/08, phthao05 <phthao05 at gmail.com> wrote:> 1) I don't know why PCA rotation function not run although I try many times. > Would you please hepl me and explain how to read the PCA map (both of > rotated and unrotated) in a concrete example.If you used the example from here [1], there's a typo in the document. It should look like the following: library(psych) fit <- factor.pa(mydata, nfactors=3, rotate="varimax") # rotatE; not rotatION fit # print results Also, there are a _lot_ of rotation methods in GPArotation. Load the package and use in the function above, say, rotate="quartimax". For un-rotated PCA, I'd imagine it would be rotate="none". Liviu [1] http://www.statmethods.net/advstats/factor.html