Hi,
Is this what you want?
##############
mytable <- read.table(textConnection("
id col1 col2 col3
10 0 4 8
11 1 2 2
12 0 8 3
13 0 5 5
"), header = TRUE)
mytable
columnname <- "col3"
mytable[order(mytable[, columnname]), ]
###################
Josh
On Mon, Jul 26, 2010 at 11:54 AM, mirek wyczesany
<miroslaw.wyczesany at uj.edu.pl> wrote:
> Hello,
>
> In my script I would like to use a loop, which sorts the dataframe according
> to different columns, pointed by the string variable.
>
> id col1 col2 col3
> 1 10 0 4 8
> 2 11 1 2 2
> 3 12 0 8 3
> 4 13 0 5 5
>
> Usually the order() function can be used like this:
>
> sorted = mytable**[order(column3) , ]
>
> which results in properly sorted table:
> **
>
> id col1 col2 col3
> 2 11 1 2 2
> 3 12 0 8 3
> 4 13 0 5 5
> 1 10 0 4 8
>
> **But when trying to use a string variable instead of "column3" name:
>
> columnname = "column3"
> **sorted = mytable**[order(columnname) , ]**
>
> this command is not properly evaluated and the effect is somewhat strange.
>
> Would you suggest some solution?
>
> Thanks a lot!
>
> Mirek
>
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>
--
Joshua Wiley
Ph.D. Student, Health Psychology
University of California, Los Angeles
http://www.joshuawiley.com/