[R] Sorting a Data Frame

Uwe Ligges ligges at statistik.tu-dortmund.de
Sat Jan 23 01:28:45 CET 2016



On 23.01.2016 01:21, Robert Sherry wrote:
> In R, I run the following commands:
>      df = data.frame( x=runif(10), y=runif(10) )
>      df2 = df[order(x),]


You use another x from your workspace, you actually want to


  df2 = df[order(df[,"x"]),]

Best,
Uwe Ligges


>
> The first, as I would expect, creates a data frame with two columns and
> 10 rows. I expect the second to sort the data based upon
> the columns x and produce a new data frame, df2, with the same size as
> df. However, the data frame is produces is much larger.
> I do not understand what is going on. I am hoping somebody can help me.
> I am also wondering if I should have a comma after
> order(x) in the second statement. I do not see a purpose for it but it
> was in an example on the web.
>
> Thanks
> Bob
>
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