On 10-Nov-07 14:25:32, affy snp wrote: > Dear list, > I am wondering how to log-2 based transform a matrix > with numeric values? > I tried > CGHlog2<-log2(CGH) but got an error. Then I > found for log2(x) in R, the x has to be a numeric or > complex vector. Any method for a matrix?
Yes, simply the method you tried: log2(M) where M is the matrix of numeric/complex datavalues. log2() will work just as well on a dataframe whose contents are numerical, as on a simple matrix: M<-data.frame(A=c(1,2,3,4),B=c(2,3,4,5),C=c(3,4,5,6)) log2(M) A B C 1 0.000000 1.000000 1.584963 2 1.000000 1.584963 2.000000 3 1.584963 2.000000 2.321928 4 2.000000 2.321928 2.584963 >From the error message you quote below, it looks as though you have made a mess of reading in, or constructing, the dataframe (the output looks like a series of several variables names, all concatenated together into one long string value). Hoping this helps! Ted. > Thanks a lot and have a good weekend! > > Allen > > >>Error in Math.data.frame(CGH) : > non-numeric variable in data frame: > WM806SignalAWM1716SignalAWM1862SignalAWM1963SignalAWM1968SignalAWM1976Si > gnalAWM3228SignalAWM3457SignalAWM3061SignalAWM3246SignalAWM3282SignalAWM > 1931SignalAWM1026SignalAWM3670SignalAWM3702SignalAWM3482SignalAWM3311Sig > nalAWM1960SignalAWM1720SignalAWM3215SignalAWM3451SignalAWM3130SignalAWM2 > 029SignalAWM3243NCI.A5SignalAWM1745SignalAWM3526SignalAWM3682SignalAWM36 > 23SignalAWM3450SignalAWM853.2SignalAWM1930SignalAWM3244NCI.BSignalAWM984 > SignalAWM3619SignalAWM3297SignalAWM451LuSignalAWM3077SignalAWM3381ASigna > lAWM3627S > ignalAWM3218SignalAWM3163SignalAWM3259SignalAWM3506SignalAWM3629SignalAW > M3456SignalAWM1346SignalAWM1852SignalARCC13NSignalAJAPOV46NSignalAJAPOV7 > 5NSignalAS004285NSignalARCC50NSignalAJAPOV54NSignalAJAPOV92NSignalARCC56 > NSignalAS004288NSignalAS004295NSignalAS004292NSignalAJAPOV73NSignalAJAPO > V52NSignalARCC53NSignalAS004289NSignalARCC25NSignalAS004294NSignalAS0042 > 75NSignalAJAPOV32NSignalACN37SignalACN16SignalAS004291NSignalACN17Signal > ARCC129NS > > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide > http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. -------------------------------------------------------------------- E-Mail: (Ted Harding) <[EMAIL PROTECTED]> Fax-to-email: +44 (0)870 094 0861 Date: 10-Nov-07 Time: 14:43:42 ------------------------------ XFMail ------------------------------ ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.