[R] The "$" operator and vectors

[Peter Dalgaard]

Gustaf Rydevik wrote:
> Hi all,
>
> I've run into a slightly illogical (to me) behaviour with the "$"
> subsetting function.
>
> consider:
>   
>> Test
>>     
>   A B
> 1 1 Q
> 2 2 R
>
>   
>> Test$A
>>     
> [1] 1 2
>
>   
>> vector<-"A"
>> Test$vector
>>     
> NULL
>
>   
>> Test$"A"
>>     
> [1] 1 2
>
>   
>> Test[,vector]
>>     
> [1] 1 2
>
>
> Is there a reason for the $ operator not evaluating the vector before executing?
>   
Yes, the evaluation rule for "$" is like that....

Notice that it also didn't go looking for an object called A when you
said test$A.


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