R help - Oct 2008 - Incorrect order

I am using the order function and the result seems to be incorrect:
> a<-c(20,30,15,40)
> order(a)
[1] 3 1 2 4

Any suggestions?

Thanks,
Laura

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What's wrong with that result?
you should look at the result as: first take the 3th element of a, then the
first one, than the second one and then the fourth.

if you do a[order(a)] then you get 15,20,30,40.

I suppose you expected:
rank(a)
[1] 2 3 1 4

Good luck

Bart


lll73 wrote:
> 
> 
> I am using the order function and the result seems to be incorrect:
> 
>> a<-c(20,30,15,40)
>> order(a)
> [1] 3 1 2 4
> 
> Any suggestions?
> 
> Thanks,
> Laura
> 
> 
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http://www.nabble.com/Incorrect-order-tp20224993p20225235.html
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Laura,

Order works fine. The output tells you that the third element of a is
the smallest, the first element is a second smallest, ... Try
a[order(a)] that should be equal to sort(a).

HTH,

Thierry


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ir. Thierry Onkelinx
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-----Oorspronkelijk bericht-----
Van: r-help-bounces op r-project.org [mailto:r-help-bounces op r-project.org]
Namens lll73
Verzonden: woensdag 29 oktober 2008 12:18
Aan: r-help op r-project.org
Onderwerp: [R] Incorrect order



I am using the order function and the result seems to be incorrect:
> a<-c(20,30,15,40)
> order(a)
[1] 3 1 2 4

Any suggestions?

Thanks,
Laura

-- 
View this message in context:
http://www.nabble.com/Incorrect-order-tp20224993p20224993.html
Sent from the R help mailing list archive at Nabble.com.

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Hi,

I believe Bart answered to your question. What is the solution you are 
expecting? If you don't give us more explanations we cannot understand 
what is wrong for you.

 > help(sort)
|order| returns a permutation which rearranges its first argument into 
ascending or descending order, breaking ties by further arguments. 
|sort.list| is the same, using only one argument.
See the examples for how to use these functions to sort data frames, etc.

In the section "see also" of the help about sort there are the two 
functions sort and rank!

 > a<-c(20,30,15,40)
 > sort(a)
[1] 15 20 30 40
 > order(a)
[1] 3 1 2 4
 > rank(a)
[1] 2 3 1 4


Alain




lll73 wrote:
> I am using the order function and the result seems to be incorrect:
>
>   
>> a<-c(20,30,15,40)
>> order(a)
>>     
> [1] 3 1 2 4
>
> Any suggestions?
>
> Thanks,
> Laura
>
>   
-- 
Alain Guillet
Statistician and Computer Scientist

Institut de statistique - Université catholique de Louvain
Bureau d.126
Voie du Roman Pays, 20
B-1348 Louvain-la-Neuve
Belgium

tel: +32 10 47 30 50


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