[R] smart way to turn a vector into a matrix

[Erik Iverson]

Hello,

anna wrote:
> Hello guys, I am working on a matrix which looks like this one:
>> initialMatrix <-
>> rbind(cbind(rep("A",3),seq(1,3)),cbind(rep("B",4),seq(1,4)),cbind(rep("C",3),seq(1,3)))
>> initialMatrix
>       [,1] [,2]
>  [1,] "A"  "1" 
>  [2,] "A"  "2" 
>  [3,] "A"  "3" 
>  [4,] "B"  "1" 
>  [5,] "B"  "2" 
>  [6,] "B"  "3" 
>  [7,] "B"  "4" 
>  [8,] "C"  "1" 
>  [9,] "C"  "2" 
> [10,] "C"  "3" 
> 
> and I would like to turn it into a list that looks like that but don't know
> which operation to apply on it:
>> myList<-list()
>> myList[[1]]<-cbind(rep("A",3),seq(1,3))
>> myList[[2]]<-cbind(rep("B",4),seq(1,4))
>> myList[[3]]<-cbind(rep("C",3),seq(1,3))
>> myList
> [[1]]
>      [,1] [,2]
> [1,] "A"  "1" 
> [2,] "A"  "2" 
> [3,] "A"  "3" 
> 
> [[2]]
>      [,1] [,2]
> [1,] "B"  "1" 
> [2,] "B"  "2" 
> [3,] "B"  "3" 
> [4,] "B"  "4" 
> 
> [[3]]
>      [,1] [,2]
> [1,] "C"  "1" 
> [2,] "C"  "2" 
> [3,] "C"  "3" 
>  I thought about a using which and lapply but didn't get to a solution.
> There is always a smart way to do it I'm sure but I'm not finding it...Can
> somebody help please?

sapply(split(initialMatrix, f = initialMatrix[,1]), matrix, ncol = 2)