[R] matrix merge problem

[Luc Villandre]

Hi Juan,

Your first question can be answered easily.

bin.matrix = matrix(A %in% B,nrow(A),ncol(A)) ;
bin.vector = rowSums(bin.matrix) > 0 ;
C = A[bin.vector,] ;

This should do the trick.

Cheers,

Luc

Juan Pablo Fededa wrote:
> Dear r-help contributors,
>
> I have two questions:
>
> first:
>
> I have a matrix A and a vector B.
> I want to make a new matrix C, which is made of the rows of A having a value
> included in B.
>
> Second:
>
> I have two matrixes A and B, of different dimensions.
> B has unique values in column 2 and A has not unique values on column 2.
> I want to merge this two matrixes by the values in the columns 2 of B and 2
> of A in such a way that the resulting matrix will be C:
>
>
> A:
>
> 1 2
> 2 2
> 3 3
> 4 3
> 5 4
> 6 4
> 7 5
> 8 5
>
>
> B:
>
> 1 2  x c d
> 2 3  y f  g
>
> C:
>
> 1 2  x c d
> 2 2  x c d
> 3 3  y f  g
> 4 3  y f  g
> 5 4 NA NA
> 6 4 NA NA
> 7 5 NA NA
> 8 5 NA NA
>
>
> Can you help me?
>
>
> Many thanks in advance.
>
> 	[[alternative HTML version deleted]]
>
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