[R] frequency table for a list matching some conditions

[Olga Lyashevska]

Thanks Dimitris,

It works nicely!

Regards,
Olga

On Thu, 2010-08-26 at 11:55 +0200, Dimitris Rizopoulos wrote: 
> one way is the following:
> 
> mylist <- list(x1 = c("A","A","A","B","C","Z","Y"),
>      x2 = c("D","D","E","E","F","Z","X"),
>      x3 = c("A","A","A","B","Y","Z"))
> newlist <- c("A","B","C","D","E","F")
> 
> 
> tab <- t(sapply(mylist, function (x)
>      table(factor(x, levels = newlist))))
> tab[tab == 0] <- NA
> tab