[R] numbers loop in R

jim holtman jholtman at gmail.com
Fri Apr 17 19:19:07 CEST 2009


try this:

> matrixx<-function(A){
+     B=matrix(NaN,nrow=(A+1),ncol=4)
+     k <- 1
+     for (i in 3:A){
+         for (j in i:A) {
+             B[k,] <- c(NaN, i-2, i-1, j)
+             k <- k + 1
+         }
+     }
+     B
+ }
> matrixx(5)
     [,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
>


On Fri, Apr 17, 2009 at 11:11 AM, emj83 <stp08emj at shef.ac.uk> 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.
>
> ______________________________________________
> 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.
>



-- 
Jim Holtman
Cincinnati, OH
+1 513 646 9390

What is the problem that you are trying to solve?




More information about the R-help mailing list