It's not clear to me at all what the OP is actually after, given the follow-up comments. It's possible they are actually looking for a way to write the data to file.
But let's assume that we're really after a way to cbind multiple data frames of differing lengths.
cbind will eventually call data.frame, whose help files says:
Objects passed to data.frame should have the same number of rows, but
atomic vectors, factors and character vectors protected by I will be
recycled a whole number of times if necessary (including as from R
2.9.0, elements of list arguments).
so in the OP's actual example, there shouldn't be an error, as R ought to recycle the shorter vectors to be of length 50. Indeed, when I run the following:
set.seed(1)
a <- runif(50)
b <- 1:50
c <- rep(LETTERS[1:5],length.out = 50)
dat1 <- data.frame(a,b,c)
dat2 <- data.frame(d = runif(10),e = runif(10))
cbind(dat1,dat2)
I get no errors and the shorter data frame is recycled as expected. However, when I run this:
set.seed(1)
a <- runif(50)
b <- 1:50
c <- rep(LETTERS[1:5],length.out = 50)
dat1 <- data.frame(a,b,c)
dat2 <- data.frame(d = runif(9), e = runif(9))
cbind(dat1,dat2)
I get the following error:
Error in data.frame(..., check.names = FALSE) :
arguments imply differing number of rows: 50, 9
But the wonderful thing about R is that you can make it do almost anything you want, even if you shouldn't. For example, here's a simple function that will cbind data frames of uneven length and automatically pad the shorter ones with NAs:
cbindPad <- function(...){
args <- list(...)
n <- sapply(args,nrow)
mx <- max(n)
pad <- function(x, mx){
if (nrow(x) < mx){
nms <- colnames(x)
padTemp <- matrix(NA, mx - nrow(x), ncol(x))
colnames(padTemp) <- nms
if (ncol(x)==0) {
return(padTemp)
} else {
return(rbind(x,padTemp))
}
}
else{
return(x)
}
}
rs <- lapply(args,pad,mx)
return(do.call(cbind,rs))
}
which can be used like this:
set.seed(1)
a <- runif(50)
b <- 1:50
c <- rep(LETTERS[1:5],length.out = 50)
dat1 <- data.frame(a,b,c)
dat2 <- data.frame(d = runif(10),e = runif(10))
dat3 <- data.frame(d = runif(9), e = runif(9))
cbindPad(dat1,dat2,dat3)
I make no guarantees that this function works in all cases; it is meant as an example only.
EDIT
If the primary goal is to create a csv or text file, all you need to do it alter the function to pad using "" rather than NA and then do something like this:
dat <- cbindPad(dat1,dat2,dat3)
rs <- as.data.frame(apply(dat,1,function(x){paste(as.character(x),collapse=",")}))
and then use write.table on rs.
merge(). Please clarify. – Iteratormergeby rowname is what you want here. – Chase