[R] adding a row to a matrix

[Gabor Grothendieck]

Try this:

t(t(a)+b)

On 4/9/06, Tim Smith <tim_smith_666 at yahoo.com> wrote:
> Hi All,
>  This is probably a very simple question. I was trying to add a row to the rows in a matrix. For example:
>
>  > a <- matrix(1:6,2,3)
> >
> > b <- a[1,]
> >
> > print(a)
>     [,1] [,2] [,3]
> [1,]    1    3    5
> [2,]    2    4    6
> >
> > print(b)
> [1] 1 3 5
>
>  I now want to add 'b' to every row of 'a', so the end result should look like:
>       [,1] [,2] [,3]
> [1,]    2    6   10
> [2,]    3    7   11
>
>  But if I do c = apply(a,1,"+",b), I get:
>  > c
>     [,1] [,2]
> [1,]    2    3
> [2,]    6    7
> [3,]   10   11
>  Now, I could easily transform this to get what I want, but I'd like to know how I could get the result without many intermediate steps ( I have large matrices, so transforming them at each step would not be efficient).
>
>  If someone could point me in the right direction, that would be a great help.
>
>  thanks.
>
>
>
>
>
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