[R] get index of current element in vector

[Uwe Ligges]

On 05.06.2012 14:46, jim holtman wrote:
> Do we need an "Obfuscated R" contest?


I already know potential winners....

Uwe





>
> On Tue, Jun 5, 2012 at 8:17 AM, Uwe Ligges
> <ligges at statistik.tu-dortmund.de>  wrote:
>>
>>
>> On 05.06.2012 00:36, Erdal Karaca wrote:
>>>
>>> Thanks all, that worked!
>>>
>>> Yes, it should be
>>> for (i in 1:length(a)) a[i]<- scalar * a[i] * i
>>>
>>> And now is...
>>>
>>> a<- a * scalar * seq_along(a)
>>>
>>> That is almost as cool as the PERL programming language :-)
>>
>>
>>
>> Almost?
>>
>> Uwe Ligges
>>
>>
>>
>>
>>> 2012/6/4 Rui Barradas<ruipbarradas at sapo.pt>
>>>
>>>> Hello,
>>>>
>>>> Just learning the alphabet? If yes, there's a difference between 'v' and
>>>> 'a'.
>>>>
>>>> Now more seriously. Your description and your loop don't do the same.
>>>>
>>>> Description:
>>>> vm<- scalar * v * seq_along(v)
>>>>
>>>> Loop:
>>>> a<- scalar * a
>>>>
>>>> Also, seq_along is the way to do it, it works even if length(a) == 0.
>>>>
>>>> Hope this helps,
>>>>
>>>> Rui Barradas
>>>>
>>>> Em 04-06-2012 21:25, Erdal Karaca escreveu:
>>>>
>>>>> (Just learning R)
>>>>>
>>>>> I have this vector:
>>>>>
>>>>> v<- c(1:10)
>>>>>
>>>>> Now, I want to multiply each element of that vector with a scalar value
>>>>> multiplied with its index:
>>>>>
>>>>> vm<- v * scalar * indexOfCurrentElementOf_v
>>>>>
>>>>> Is that possible without using a loop?
>>>>>
>>>>> In a loop I would do this:
>>>>>
>>>>> for (i in 1:length(a)) a[i]<- scalar * a[i]
>>>>>
>>>>>         [[alternative HTML version deleted]]
>>>>>
>>>>> ______________________________________________
>>>>> R-help at r-project.org mailing list
>>>>> https://stat.ethz.ch/mailman/listinfo/r-help
>>>>> PLEASE do read the posting guide
>>>>> http://www.R-project.org/posting-guide.html
>>>>> and provide commented, minimal, self-contained, reproducible code.
>>>>>
>>>>
>>>
>>>         [[alternative HTML version deleted]]
>>>
>>> ______________________________________________
>>> R-help at r-project.org mailing list
>>> https://stat.ethz.ch/mailman/listinfo/r-help
>>> PLEASE do read the posting guide
>>> http://www.R-project.org/posting-guide.html
>>> and provide commented, minimal, self-contained, reproducible code.
>>
>>
>> ______________________________________________
>> R-help at r-project.org mailing list
>> https://stat.ethz.ch/mailman/listinfo/r-help
>> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
>
>
>