[R] Sorting a data frame
Marc Schwartz
MSchwartz at medanalytics.com
Wed Jul 16 16:41:24 CEST 2003
On Wed, 2003-07-16 at 08:42, Wayne Jones wrote:
> Hi there R-Helpers,
>
> Does anyone know if it is possible to sort a dataframe?
>
> I.e. Sort alphabetically column 1 ( which has some reocurring elements) then
> sort alphabetically column2 but keeping the order of column 1 constant;
> much the same way that the sort function works in Excel.
>
> Regards,
>
> Wayne
Wayne,
Use order() to sort the columns. This allows for multi-level keys. See
?order for more information.
Example:
# Create two column df
> df <- data.frame(V1 = c("W","A", "A", "B", ""), V2 = c("E", "M", "B",
"O", "Q"))
# show df unsorted
> df
V1 V2
1 W E
2 A M
3 A B
4 B O
5 Q
# now sort df, by V1, then V2
> df[order(df$V1, df$V2), ]
V1 V2
5 Q
3 A B
2 A M
4 B O
1 W E
Note that rows 2 and 3 are subsorted on V2.
HTH,
Marc Schwartz
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