# [R] numbers loop in R

David Winsemius dwinsemius at comcast.net
Fri Apr 17 19:13:25 CEST 2009

```I would have expected to see the assignment to B[k,] inside the loops.
And to see some connection with the k index in the inner loops if you
did not want all of the rows to be similar. Because the assignment is
outside the loops, it happens only once.

-- David Winsemius

On Apr 17, 2009, at 11:11 AM, emj83 wrote:

>
> I would like to create a matrix in R that looks similar to this:
>
>     [,1] [,2] [,3] [,4]
> [1,]  NaN  1  2  3
> [2,]  NaN  1  2  4
> [3,]  NaN   1  2  5
> [4,]  NaN  2  3  4
> [5,]  NaN  2  3  5
> [6,]  NaN    3    4    5
>
> I have the loop below:
>
> where A for example is 5
>
> matrixx<-function(A){
> B=matrix(NaN,nrow=(A+1),ncol=4)
>        for(k in 1:(A+1)){
> 	        for(i in 1:(A-2)){
> 		     for(j in (i+2):A){
> 		     }
> 		}
>       }
> B[k,]=c(NaN,i,(i+1),j)
> print(B)
> }
>
> But it only prints the final line in:
>
>> matrixx(5)
>     [,1] [,2] [,3] [,4]
> [1,]  NaN  NaN  NaN  NaN
> [2,]  NaN  NaN  NaN  NaN
> [3,]  NaN  NaN  NaN  NaN
> [4,]  NaN  NaN  NaN  NaN
> [5,]  NaN  NaN  NaN  NaN
> [6,]  NaN    3    4    5
>
> Could anyone give me a hand? Would be much appreciated.
>
> Thanks Emma
>
> --
> View this message in context: http://www.nabble.com/numbers-loop-in-R-tp23099591p23099591.html
> Sent from the R help mailing list archive at Nabble.com.
>
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> and provide commented, minimal, self-contained, reproducible code.

David Winsemius, MD
Heritage Laboratories
West Hartford, CT

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