Amarjit Singh Sethi
2011-Apr-09 03:22 UTC
[R] How to define a number of matrices through loops
Hi all
I need to deal with a number (say, 5) of diferent ordered matrices?
simultaneously?in my computational work. I tried to define these matrices
through looping, but got an error message:
row <- c(3,4,6,4,5)
mt <- c()
for (i in 1:5){?
mt[i] <- matrix(nrow=row[i],ncol=4)
}
mt
Kindly help
Yours
ajss
Hi Ajss,
You instantiated mt as a vector, not a list. Try:
row <- c(3,4,6,4,5)
mt <- vector("list", length(row)) # list with length of
"row" elements
for (i in 1:5){
mt[[i]] <- matrix(nrow=row[i], ncol=4)
}
mt
Or in one line:
mt <- lapply(1:5, function(x) matrix(nrow = x, ncol = 4))
mt
Hope this helps,
Josh
On Fri, Apr 8, 2011 at 8:22 PM, Amarjit Singh Sethi <set_alt at
yahoo.co.in> wrote:> Hi all
> I need to deal with a number (say, 5) of diferent ordered matrices
> simultaneously?in my computational work. I tried to define these matrices
> through looping, but got an error message:
>
> row <- c(3,4,6,4,5)
> mt <- c()
> for (i in 1:5){
> mt[i] <- matrix(nrow=row[i],ncol=4)
> }
> mt
>
> Kindly help
>
> Yours
> ajss
>
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--
Joshua Wiley
Ph.D. Student, Health Psychology
University of California, Los Angeles
http://www.joshuawiley.com/