[R] inserting columns in the middle of a dataframe

Joe W. Byers Joe-Byers at utulsa.edu
Fri Sep 29 05:11:45 CEST 2006


Berton Gunter wrote:
> Please folks -- use indexing.
> 
> myframe<-myframe[,c(1,5,2,3,4)]
> 
> Which begs the question: why bother rearranging the columns anyway, since
> one can get them used, printed, etc. in any order you wish anytime you want
> just by specifying the indices in the order you want them. I suspect the
> question was motivated by too much Sas- or Excel -ism.
Many of the time series classes expect a date in the first column of the 
matrix or data.frame when creating the date-time object.  Retrieving 
data in a SQL query from a dB returns a character representation of the 
date that requires conversion to a date.  Performing this conversion is 
easy but inserting this converted date column is not straight forward.


> 
> -- Bert Gunter
> Genentech Non-Clinical Statistics
> South San Francisco, CA
>  
> "The business of the statistician is to catalyze the scientific learning
> process."  - George E. P. Box
>  
>  
> 
>> -----Original Message-----
>> From: r-help-bounces at stat.math.ethz.ch 
>> [mailto:r-help-bounces at stat.math.ethz.ch] On Behalf Of Timothy Bates
>> Sent: Wednesday, September 13, 2006 3:05 PM
>> To: Jon Minton; r-help at stat.math.ethz.ch
>> Subject: Re: [R] inserting columns in the middle of a dataframe
>>
>>
>>> Is there a built-in and simple way to insert new columns in 
>> a dataframe?
>>
>> You do this by collecting the columns in the new order you desire, and
>> making a new frame.
>>
>> oldframe           <- data.frame(matrix(0:14,ncol=3))
>> newcol              <- data.frame(20:24)
>> names(newcol) <- "newcol"
>> newframe         <- data.frame(c(oldframe[1],newcol, oldframe[2:3]))
>>
>> ______________________________________________
>> R-help at stat.math.ethz.ch mailing list
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>> PLEASE do read the posting guide 
>> http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
>>
> 
> ______________________________________________
> 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.
>



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