Message-ID: <CAAmySGOyc5EVmgCmrEi2qFLBX8FGbtrGbTdu=gP+xMLH5RohdQ@mail.gmail.com>
Date: 2011-11-30T14:17:19Z
From: R. Michael Weylandt
Subject: how to call a function for each row
In-Reply-To: <1322658608657-4122906.post@n4.nabble.com>
Read ?apply
This is easiest:
df <- matrix(c(1,2,3,3,4,6,5,6,1), 3)
apply(df, 1, function(x) 6*x[1]+7*x[2]+8*x[3])
But it's much more efficient to do it with matrix multiplication. In
keeping with the best of tradition, this is left as an exercise to the
reader.
Michael
On Wed, Nov 30, 2011 at 8:10 AM, arunkumar1111 <akpbond007 at gmail.com> wrote:
> Hi
>
> ?I have ?a data-frame which look like this
>
> X1 X2 X3
> 1 ? 3 ?5
> 2 ? 4 ?6
> 3 ? 6 ?1
>
> I want to apply a formula Y=6*X1 + 7*X2 + 8*X3 ?for every row
>
>
> Thanks in Advance
>
>
>
>
>
>
>
> --
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>
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