The order() function in R is not giving me the right results

Asked Mar 22 '18 at 13:44

Active Mar 22 '18 at 13:57

Viewed 82 times

I had a dataset I was working with and I wanted to use order to sort values in a df column. But I did not get the right results. I checked format, and it was all numeric.

Then I loaded the mtcars data set built into R and also did not get the right results, i would like to know why that is:

enter image description here

edited Mar 22 '18 at 13:50

lebelinoz

4,662
10
29
53

asked Mar 22 '18 at 13:44

Nauman Ahmed

1

try sort() instead ?? – Zahiro Mor Mar 22 '18 at 13:44
1

See `?order` and try `mtcars[order(mtcars$hp),]`. – nicola Mar 22 '18 at 13:48
2

I find it implausible that they are not giving you the right results. More likely, you are not interpreting the results correctly. `order()` gives you a permutation of the indices, one which corresponds to the sort order. It doesn't directly sort the data. – John Coleman Mar 22 '18 at 13:48
Do you mean `mtcars[order(mtcars$hp),]`? – 1.618 Mar 22 '18 at 13:48
1

`order` returns the ranks of the vector. `sort` returns the sorted vector itself. Notice how `identical(mtcars$hp[order(mtcars$hp)], sort(mtcars$hp))` evaluates to `TRUE`. – ngm Mar 22 '18 at 13:49
2

@ngm, `order` does not return the ranks. `o – G. Grothendieck Mar 22 '18 at 13:51
1

Seems like a duplicate of: [Understanding the order() function](https://stackoverflow.com/q/2315601/4996248) – John Coleman Mar 22 '18 at 13:55
I was interpretting the results wrong. I should have used rank() function instead of order(). – Nauman Ahmed Mar 23 '18 at 14:43
Thank you all for the help. I looked into it more and understood the difference between order() and rank() – Nauman Ahmed Mar 23 '18 at 14:44

The order() function in R is not giving me the right results

0 Answers0