[R] How to compare rows of two matrices

Muhammad Subianto msubianto at gmail.com
Thu Aug 24 18:23:12 CEST 2006


Dear Stephen C. Upton & Petr Pikal
Thank you both very much for the suggestions!

Best wishes, Muhammad Subianto

On this day 24/08/2006 12:03, Muhammad Subianto wrote:
> Dear all,
> I have a dataset
> train <- cbind(c(0,2,2,1,0), c(8,9,4,0,2), 6:10, c(-1, 1, 1, -1, 1))
> test <- cbind(1:5, c(0,1,5,1,3), c(1,1,2,0,3) ,c(1, 1, -1, 1, 1))
>
> I want to find which rows of train and test it different in its last
> column (column 4).
> The solution must be something like
>
> train
>     [,1] [,2] [,3] [,4]
> [1,]    0    8    6   -1
> [3,]    2    4    8    1
> [4,]    1    0    9   -1
>
>
> test
>     [,1] [,2] [,3] [,4]
> [1,]    1    0    1    1
> [3,]    3    5    2   -1
> [4,]    4    1    0    1
>
> I have tried with
> matrix(train %in% test, dim(train))
> apply(train, 1, paste, collapse="") %in% apply(test, 1, paste, 
> collapse="")
>
> It doesn't work.
> How can I do.
> Thanks for any help.
>
> Best, Muhammad Subianto
>



More information about the R-help mailing list