[R] element-by-element comparison

Patrick Burns pburns at pburns.seanet.com
Sun Oct 30 09:44:10 CET 2011


Given that you want to compare
columns, you can just do:

A > B

If you wanted to compare rows, then
it is more troublesome.  One approach
would be:

rep(A, each=nrow(B)) > B


On 30/10/2011 03:51, Wendy wrote:
> Hi,
>
> I have a vector and a matrix. For example,
>
> A = [
> 12
> 3
> 4];
>
> B = [
> 4       13
> 10      2
> 4       8];
>
> I am comparing A to each column of B using A>B[,ii], so the expected result
> is
>
> C = [
> 1    0
> 0    1
> 0    0];
>
> I am looking for a way to do this quickly instead of going through the for
> loop, but haven't had any luck yet? Any advice is appreciated.
>
> Thank you very much.
>
> Wendy
>
>
>
>
>
>
> --
> View this message in context: http://r.789695.n4.nabble.com/element-by-element-comparison-tp3952301p3952301.html
> Sent from the R help mailing list archive at Nabble.com.
>
> ______________________________________________
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> and provide commented, minimal, self-contained, reproducible code.
>

-- 
Patrick Burns
pburns at pburns.seanet.com
twitter: @portfolioprobe
http://www.portfolioprobe.com/blog
http://www.burns-stat.com
(home of 'Some hints for the R beginner'
and 'The R Inferno')



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