[R] Help How to use a loop to do pair comparison

[Patrick Burns]

One possible first step could be:

ifelse(outer(x, x, '>'), 'Big', 'Small')


Patrick Burns
patrick at burns-stat.com
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http://www.burns-stat.com
(home of "The R Inferno" and "A Guide for the Unwilling S User")

Chunhao Tu wrote:
> Hi R users,
>
> I have a question. How can I use for loop to do pair comparisons. For
> example,
>
>   
>> x<-c(1,2,3)
>>     
>
>   
>> result<-matrix(data=NA, nrow=choose(3,2), ncol=1)
>>     
>
>   
>> for(i in 1: length(x))
>>     
>
> +    { result[i,]<-ifelse(x[i] > x[i+1], yes="Big", no="Small")
>
> +     result}
>
>   
>> result
>>     
>
>      [,1]   
>
> [1,] "Small"
>
> [2,] "Small"
>
> [3,] NA     
>
>  
>
> I want to compare (1 vs. 2), (1 vs. 3), (2 vs.3) 
>
> I know I miss something but I just can not get it work. Could anyone give me
> a hint?
>
>  
>
> Appreciate,
>
> Chunhao 
>
>
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>
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