[R] read.table with numeric row names

peter dalgaard pdalgd at gmail.com
Fri Jul 13 16:27:53 CEST 2012


On Jul 13, 2012, at 04:27 , arun wrote:

> Hello,
> 
> I saw your reply in nabble.  Sorry about that.  I thought the dataset had only few columns.
> 
> #You can read first line of a file using:
> readLines("foo.txt",n=1)[1]
> 
> 
> #The more generic colname substitution
> dat1<-read.table(text=" 
>  2.5  3.6  7.1  7.9 
>  100  3      4      2    3 
>  200  3.1  4      3      3 
>  300  2.2  3.3  2    4 
>  ",sep="",header=TRUE)

(This didn't survive too well in mail:

> dat1<-read.table(text=" 
+  2.5  3.6  7.1  7.9 
+  100  3      4      2    3 
+  200  3.1  4      3      3 
+  300  2.2  3.3  2    4 
+  ",sep="",header=TRUE)  
Error in read.table(text = " \n 2.5  3.6  7.1  7.9 \n 100  3      4      2    3 \n 200  3.1  4      3      3 \n 300  2.2  3.3  2    4 \n ",  : 
  more columns than column names

Not sure exactly what happened there...)

 

>  
> #The code should remove the "X" from the column names (row names?)
> 

However, adding check.names=FALSE should be more expedient.

> colnames(dat1)<-gsub("^[X](.*)","\\1",colnames(dat1))
> dat1
>     2.5 3.6 7.1 7.9
> 100 3.0 4.0   2   3
> 200 3.1 4.0   3   3
> 300 2.2 3.3   2   4
> plot(colMeans(dat1)~as.numeric(names(dat1)),xlab="Column_Name",ylab="Column_Mean")
> 
> A.K.
> 
> 
> 
> 
> ----- Original Message -----
> From: kexinz <zhangchicool at gmail.com>
> To: r-help at r-project.org
> Cc: 
> Sent: Thursday, July 12, 2012 2:50 PM
> Subject: [R] read.table with numeric row names
> 
> I have a text file like this
>          2.5  3.6  7.1  7.9
> 100   3      4       2     3
> 200   3.1   4      3      3
> 300   2.2   3.3   2     4
> 
> I used "r <- read.table("a.txt", header=T)"
> The row names becomes X2.5, X3.6... What I need is the row names are
> numeric, so I can use the row names as numbers on x-axis for plotting. e.g.
> "plot(colMeans(r)~names(r))", something like this. How to do this?
> 
> Thanks.
> 
> --
> View this message in context: http://r.789695.n4.nabble.com/read-table-with-numeric-row-names-tp4636342.html
> Sent from the R help mailing list archive at Nabble.com.
> 
> ______________________________________________
> R-help at r-project.org 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.
> 
> 
> ______________________________________________
> R-help at r-project.org 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.

-- 
Peter Dalgaard, Professor
Center for Statistics, Copenhagen Business School
Solbjerg Plads 3, 2000 Frederiksberg, Denmark
Phone: (+45)38153501
Email: pd.mes at cbs.dk  Priv: PDalgd at gmail.com



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