ofessor of Anthropology
> Texas A&M University
> College Station, TX 77843-4352
>
>
>
> -Original Message-
> From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On
> Behalf Of R. Michael Weylandt
> Sent: Wednesday, November 30, 2011 8:17
, 2011 8:17 AM
To: arunkumar1111
Cc: r-help@r-project.org
Subject: Re: [R] how to call a function for each row
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
Homework. ?
I would say that this indiicates that you need to open the R tutorials
and start reading.
-- Bert
On Wed, Nov 30, 2011 at 5:10 AM, arunkumar 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=
will this do it:
> x <- read.table(text = "X1 X2 X3
+ 1 3 5
+ 2 4 6
+ 3 6 1", header = TRUE)
> x
X1 X2 X3
1 1 3 5
2 2 4 6
3 3 6 1
> apply(x, 1, function(a) 6 * a[1] + 7 * a[2] + 8 * a[3])
[1] 67 88 68
>
>
On Wed, Nov 30, 2011 at 8:10 AM, arunkumar wrote:
> Hi
>
> I have
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
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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