you need to return x in the function within lapply(), e.g., something like
lapply(TP, function(x) { x[is.na(x)] <- 0; x }) I hope it works. Best, Dimitris ---- Dimitris Rizopoulos Ph.D. Student Biostatistical Centre School of Public Health Catholic University of Leuven Address: Kapucijnenvoer 35, Leuven, Belgium Tel: +32/(0)16/336899 Fax: +32/(0)16/337015 Web: http://med.kuleuven.be/biostat/ http://www.student.kuleuven.be/~m0390867/dimitris.htm ----- Original Message ----- From: "Doran, Harold" <[EMAIL PROTECTED]> To: <r-help@stat.math.ethz.ch> Sent: Wednesday, January 24, 2007 4:40 PM Subject: [R] Replace missing values in lapply >I have some matrices stored as elements in a list that I am working > with. On example is provided below as TP[[18]] > >> TP[[18]] > level2 > level1 1 2 3 4 > 1 79 0 0 0 > 2 0 0 0 0 > 3 0 0 0 0 > 4 0 0 0 0 > > Now, using prop.table on this gives > >> prop.table(TP[[18]],1) > level2 > level1 1 2 3 4 > 1 1 0 0 0 > 2 > 3 > 4 > > It is important for the zero's to retain their position as this > matrix > will subsequently be used in some matrix multiplication and hence, > must > be of dimension 4 by 4 so that is it conformable for multiplcation > with > another matrix. > > In looking at the structure of the object resulting from prop.table > I > see NaNs, and so I can do this > >> rr <- TP[[18]] >> rr[is.na(rr)] <- 0 >> rr > level2 > level1 1 2 3 4 > 1 79 0 0 0 > 2 0 0 0 0 > 3 0 0 0 0 > 4 0 0 0 0 > > This is exactly what I want for each matrix. But, I have multiple > matrices stored within the list that need to be changed and so I am > trying to resolve this via lapply, but something is awry (namely the > user), but I could use a little help. > > I was thinking the following function should work, but it doesn't. > It > reduces each matrix within the list to a 0. > > PP <- lapply(TP, function(x) x[is.na(x)] <- 0) > > Am I missing something obvious? > > Harold > > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@stat.math.ethz.ch 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. > Disclaimer: http://www.kuleuven.be/cwis/email_disclaimer.htm ______________________________________________ R-help@stat.math.ethz.ch 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.