[R] select a subset from a sample

[Den]

Maybe that:

su <- lapply(dat[2:5],function(x)table(x))
su
mode(su)
myBYdata <- data.frame( do.call(cbind,lapply(su, as.data.frame)) )
myBYdata


У Няд, 23/01/2011 у 07:43 -0500, Wei Yang піша:
> Dear all,
> 
> I would like to ask whether anyone has experience with the problem below.
> 
> 
> I want to select a subset of the sample (see data below) so that each level
> (1,2,3,4 in the example) for every variable (v1,v2,v3,v4 in the example) is
> shown at least once in the subset.  I also want the sample size of the
> subset to be as small as possible.  Any help on it is greatly appreciated.
> 
> 
>     Id v1 v2 v3 v4
> 
> [1,]  1 1 2 4 3
> 
>  [2,]  2 2 1 3 4
> 
>  [3,]  3 4 2 4 2
> 
>  [4,]  4 1 1 2 3
> 
>  [5,]  5 3 2 3 4
> 
>  [6,]  6 3 1 1 1
> 
>  [7,]  7 3 4 3 1
> 
>  [8,]  8 4 4 4 4
> 
>  [9,]  9 1 2 2 1
> 
> [10,] 10 4 1 1 2
> 
> [11,] 11 2 4 3 2
> 
> [12,] 12 1 4 2 3
> 
> [13,] 13 2 3 3 4
> 
> [14,] 14 4 3 1 2
> 
> [15,] 15 3 2 1 2
> 
> [16,] 16 2 3 2 3
> 
> [17,] 17 1 4 1 4
> 
> [18,] 18 2 3 4 3
> 
> [19,] 19 4 1 4 1
> 
> [20,] 20 3 3 2 1
> 
> 
> 
> Thanks,
> 
> Peter
> 
> 	[[alternative HTML version deleted]]
> 
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