[R] Control the variable order after multiple declarations using within

[Sebastien Bihorel]

Hi Kevin,

I was hoping to stay within base R functionality.

Thanks

----- Original Message -----
From: "Kevin Thorpe" <kevin.thorpe using utoronto.ca>
To: "Sebastien Bihorel" <sebastien.bihorel using cognigencorp.com>
Cc: "R Help Mailing List" <r-help using r-project.org>
Sent: Wednesday, July 3, 2019 8:11:51 AM
Subject: Re: [R] Control the variable order after multiple declarations using within

> On Jul 3, 2019, at 3:15 AM, Sebastien Bihorel <sebastien.bihorel using cognigencorp.com> wrote:
> 
> Hi, 
> 
> The within function can be used to modify data.frames (among other objects). One can even provide multiple expressions to modify the data.frame by more than one expression. However, when new variables are created, they seem to be inserted in the data.frame in the opposite order they were declared: 
> 
>> df <- data.frame(a=1) 
>> within(df, {b<-a*2; c<-b*3})
>  a c b
> 1 1 6 2 
> 
> Is there a way to insert the variables in an order consistent with the order of declaration (ie, a, b, c)? 
> 

One way is to use mutate() from the dplyr package.


> Thanks 
> 
> Sebastien
> 
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-- 
Kevin E. Thorpe
Head of Biostatistics,  Applied Health Research Centre (AHRC)
Li Ka Shing Knowledge Institute of St. Michael's
Assistant Professor, Dalla Lana School of Public Health
University of Toronto
email: kevin.thorpe using utoronto.ca  Tel: 416.864.5776  Fax: 416.864.3016