?? Maybe: do.call(rbind, list.of.your;matrices)
?do.call (if you can't do it with explicit loops (i.e. for(), while()), apply type functions are probably not what you want). -- Bert On Thu, Apr 19, 2012 at 2:28 PM, Worik R <wor...@gmail.com> wrote: > Friends > > I clearly donot understand how sapply and vapply work. > > What I have is a function that returns a matrix with an indeterminate > number of rows (some times zero) but a constant number of columns. I > cannot reliably use an apply function to assemble the matrices into a > matrix. I am not sure it is possible. > > I can demonstrate the core of my confusion with this simple code. > > A.f <- function(i){ > ret <- matrix("a", i, 7) > cat(i, class(ret), dim(ret), "\n") > return(ret) > } > V.f <- function(){ > SS <- vapply(c(1,2), > A.f, > rep('a', 7)) > return(SS) > } > S.f <- function(){ > SS <- sapply(c(1,2), > A.f) > cat("SS", class(SS), dim(SS), "\n") > return(SS) > } > > > Calling V.f() fails: > >> V.f() > 1 matrix 1 7 > 2 matrix 2 7 > Error in vapply(c(1, 2), A.f, rep("a", 7)) : > values must be length 7, > but FUN(X[[2]]) result is length 14 >> > > > Calling S.f() returns a list. > > > Do I have to accept I am going to be getting a list and I have to > assemble a matrix in a loop? > > cheers > Worik > > ______________________________________________ > 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. -- Bert Gunter Genentech Nonclinical Biostatistics Internal Contact Info: Phone: 467-7374 Website: http://pharmadevelopment.roche.com/index/pdb/pdb-functional-groups/pdb-biostatistics/pdb-ncb-home.htm ______________________________________________ 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.