# Re: [R] How to define a number of matrices through loops

From: Joshua Wiley <jwiley.psych_at_gmail.com>
Date: Fri, 08 Apr 2011 21:00:42 -0700

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
>
> ______________________________________________
> R-help_at_r-project.org mailing list
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> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>

```--
Joshua Wiley
Ph.D. Student, Health Psychology
University of California, Los Angeles
http://www.joshuawiley.com/

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Received on Sat 09 Apr 2011 - 04:02:55 GMT

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