lapply?

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Hi,

the output of lapply() is a list; see ?lapply and ?sapply.

# if you know the length of your list in advance,
# this definition is better:
uu <- vector("list", 2)

# list elements
uu[[1]] <- c(1,2,3)
uu[[2]] <- c(3,4,5)

# some options to achieve what you want:
matrix(unlist(uu), 2, 3, T)
do.call(rbind, uu)
t(sapply(uu, I))

HTH,
  Denes
Hi,

I was trying to use lapply to create a matrix from a list:

uu <- list()
uu[[1]] <- c(1,2,3)
uu[[2]] <- c(3,4,5)

The output I desire is a matrix with 2 rows and 3 columns, so I try:

xx <- lapply(uu,rbind)

Obviously, I'm not doing something right, but what!?

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Hi,

I was trying to use lapply to create a matrix from a list:

uu <- list()
uu[[1]] <- c(1,2,3)
uu[[2]] <- c(3,4,5)

The output I desire is a matrix with 2 rows and 3 columns, so I try:

xx <- lapply(uu,rbind)

Obviously, I'm not doing something right, but what!?
do.call(rbind,uu) 

Berend
Hello,

You are applying rbind to each element of the list, not rbinding it with 
the others. Try instead

do.call(rbind, uu)

Hope this helps,

Rui Barradas

Em 14-11-2013 15:20, Brian Smith escreveu:
Hi,

I was trying to use lapply to create a matrix from a list:

uu <- list()
uu[[1]] <- c(1,2,3)
uu[[2]] <- c(3,4,5)

The output I desire is a matrix with 2 rows and 3 columns, so I try:

xx <- lapply(uu,rbind)

Obviously, I'm not doing something right, but what!?

	[[alternative HTML version deleted]]

______________________________________________
R-help at 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.

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