I wonder if a list of matrices is the best representation? Do your matrices all have the same dimension as in:
TP <- list(matrix(c(1:3, NA), 2), matrix(c(NA, 1:3), 2)) # Then you could consider representing them as an array: TPa <- array(unlist(TP), c(2,2,2)) # in which case its just TPa[is.na(TPa)] <- 0 TPa On 1/24/07, Doran, Harold <[EMAIL PROTECTED]> wrote: > 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. > ______________________________________________ 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.