Re: [R] Importing data in text file into R

From: John Fox <jfox_at_mcmaster.ca>
Date: Sat, 24 May 2008 00:06:47 -0400

Dear AJSS,

The problem is that the way you've read the data, the first column of the data frame is a factor, not a numerical variable, and thus is not suitable for computing correlations.

You could use the command cor(idt[,-1]) to compute correlations on all but the first column, but your intention was probably to use the first column of the input file for row names, not as a variable. One way to do this is simply to omit the variable name "Year" in the first row of the input data file.

I hope this helps,
  John

On 23-May-08, at 11:40 PM, amarjit singh sethi wrote:

> Dear all,
> I am quite new to R; facing certain problems:
> Say, I have a text file( named as "try"):
> Year C1 C2 C3 C4 C5 C6
> Y1 3.5 13.8 9.5 6.8 0.4 24.2
> Y2 3.8 13.9 9.9 7.6 0.7 12.8
> Y3 4.5 14.5 14.2 9.2 0.6 14.5
> Y4 5.9 16.2 24.6 12.7 0.2 24.3
> Y5 7.2 20.4 40.6 18.2 0.8 28.2
> Y6 5.9 18.6 37.4 14.5 0.3 36.9
> Y7 8.0 16.1 88.6 24.1 0.1 34.6
> Y8 13.6 21.1 56.3 19.0 0.7 33.3
>
> I wish to import the file into R and make certain
> computations, like intercorrelation matrix. I tried
> the following syntax:
>
> # Inputting the data file (saved in text format)
> df="trial.txt"
> idt=read.table(df,header=T, sep="\t")
> idt
> # To generate intercorrelatio matrix
> r = cor(idt)
> r=round(r, 4)
> r
>
> The seems to have been read, but further computations
> not made, with the following output:
>
>> # Inputting the data file (saved in text format)
>> df="trial.txt"
>> idt=read.table(df,header=T, sep="\t")
>> idt
> Year C1 C2 C3 C4 C5 C6
> 1 Y1 3.5 13.8 9.5 6.8 0.4 24.2
> 2 Y2 3.8 13.9 9.9 7.6 0.7 12.8
> 3 Y3 4.5 14.5 14.2 9.2 0.6 14.5
> 4 Y4 5.9 16.2 24.6 12.7 0.2 24.3
> 5 Y5 7.2 20.4 40.6 18.2 0.8 28.2
> 6 Y6 5.9 18.6 37.4 14.5 0.3 36.9
> 7 Y7 8.0 16.1 88.6 24.1 0.1 34.6
> 8 Y8 13.6 21.1 56.3 19.0 0.7 33.3
>> # To generate intercorrelatio matrix
>> r = cor(idt)
> Error in cor(idt) : missing observations in cov/cor
> In addition: Warning message:
> In cor(idt) : NAs introduced by coercion
>> r=round(r, 4)
> Error: object "r" not found
>> r
> Error: object "r" not found
>
> Kindly advise me as to how to get rid of the error
> message.
>
> AJSS
>
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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. Received on Sat 24 May 2008 - 04:09:51 GMT

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