[R] matrix merge problem

[Luc Villandre]

Hi again,

Your second problem can be solved with the "merge" function. Look at the 
help file with ?merge.

Best of luck,

Luc
 
Juan Pablo Fededa wrote:
> Merci a lot!!!!!!
>
> On Tue, Apr 14, 2009 at 10:32 PM, Luc Villandre 
> <villandl at dms.umontreal.ca <mailto:villandl at dms.umontreal.ca>> wrote:
>
>     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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