[R] Dataframe in loop

[Michael Na Li]

On Wed, 5 Mar 2003, Ronaldo Reis, Jr. verbalised:

>  Hi,
>  
>  I try to make a dataframe in a loop function, but I dont have succeed.
>  
>  The function is something like this:
>  
>  for(i in c(10,12)) {
>     expr
      ^^^^  what's this?

>        for(j in c(1:2) {
>           total <- c(1,2,3,4,5,6,7)
>           nspf <- length(levels(as.factor(total)))
>           fin <- data.frame(L=i,N=nspf)
>           print(fin)
>    }
>  }
>  

You are creating a new data frame with in each loop.

You want something like this,
,----
| > fin <- NULL
| > for(i in c(10,12)) {
| +     for(j in c(1:2)) {
| +         total <- c(1,2,3,4,5,6,7)
| +         nspf <- length(levels(as.factor(total)))
| +         fin <- rbind (fin, c(L=i, N=nspf))
| +    }
| + }
| > print(fin)
|       L N
| [1,] 10 7
| [2,] 10 7
| [3,] 12 7
| [4,] 12 7
`----


Cheers,

Michael