Message-ID: <20130314112751.Horde.6AQENmEwhY5RQaYnFbgxcXA@webmailnew.dds.nl>
Date: 2013-03-14T10:27:51Z
From: Jan van der Laan
Subject: HOw to achieve big vector times big dataframe in R?
In-Reply-To: <DUB116-W28A7337E8C594E0EEB342186EC0@phx.gbl>
apply((t(as.matrix(b)) * a), 2, sum)
should do what you want.
Why this works; see,
http://cran.r-project.org/doc/manuals/r-release/R-intro.html#The-recycling-rule and the paragraph before
that.
Jan
Tammy Ma <metal_licaling at live.com> schreef:
> HI,
>
> I have the following question:
>
> Vector a with lenght 150
>
> A B C D.........
>
> dataframe b with dim 908X150
>
> 1 1 1 1.....
> 2 2 2 2
> 3 3 3 3
> 4 4 4 4
> ................
>
> final result I want is the vector with length 908:
> A*1+B*1+C*1+D*1+.....
> A*2+B*2+C*2+D*2+.....
> A*3+B*3+C*3+D*3+.....
> A*4+B*4+C*4+D*4+.....
> ....
>
> because of too large dimension, how can I achieve this in R? Thanks.
>
> Kind Regards,
> Tammy
>
>
> [[alternative HTML version deleted]]
>
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