R help - Sep 2006 - (no subject)

Hi,

I have a problem with aggregate.

x <- aggregate(t1,list(t2,t3,t4), mean)

z<-x[,3]

I want z to be a vector but it is a factor.

I've tried to use as.vector(z,mode="numeric") but then the numbers
get
scrambeled.

Any help is appriciated

/anders

Hi

all culumns which are used for discrimination (in your case 3) are 
factor. If you want to change them to numeric you has to use

as.numeric(as.character(x[,3]))

I believe it is in FAQ.

HTH
Petr

Please use sensible subject.


On 12 Sep 2006 at 14:49, Anders Eklund wrote:

Date sent:      	Tue, 12 Sep 2006 14:49:18 +0200 (CEST)
From:           	"Anders Eklund" <aeklund at kth.se>
To:             	"r-help at lists.R-project.org" <r-help at
stat.math.ethz.ch>
Subject:        	[R] (no subject)
> Hi,
> 
> I have a problem with aggregate.
> 
> x <- aggregate(t1,list(t2,t3,t4), mean)
> 
> z<-x[,3]
> 
> I want z to be a vector but it is a factor.
> 
> I've tried to use as.vector(z,mode="numeric") but then the
numbers get
> scrambeled.
> 
> Any help is appriciated
> 
> /anders
> 
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html and provide commented,
> minimal, self-contained, reproducible code.
Petr Pikal
petr.pikal at precheza.cz

>From the FAQ:
7.10 How do I convert factors to numeric?

It may happen that when reading numeric data into R (usually, when
reading in a file), they come in as factors. If f is such a factor
object, you can use

     as.numeric(as.character(f))

to get the numbers back. More efficient, but harder to remember, is

     as.numeric(levels(f))[as.integer(f)]

In any case, do not call as.numeric() or their likes directly for the
task at hand (as as.numeric() or unclass() give the internal codes).

On 12/09/06, Anders Eklund <aeklund at kth.se>
wrote:
> Hi,
>
> I have a problem with aggregate.
>
> x <- aggregate(t1,list(t2,t3,t4), mean)
>
> z<-x[,3]
>
> I want z to be a vector but it is a factor.
>
> I've tried to use as.vector(z,mode="numeric") but then the
numbers get
> scrambeled.
>
> Any help is appriciated
>
> /anders
>
> ______________________________________________
> R-help at stat.math.ethz.ch mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide
http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>

--
================================David Barron
Said Business School
University of Oxford
Park End Street
Oxford OX1 1HP


-- 
================================David Barron
Said Business School
University of Oxford
Park End Street
Oxford OX1 1HP