[R] Efficient manipulation with list object

[Jeff Newmiller]

The question was about matrices, not data frames or data tables. While faster than Reduce, the conversions still make it over twice as slow as Rui's answer.

On June 10, 2018 12:18:39 PM HST, Benjamin Christoffersen <boennecd using gmail.com> wrote:
>You may be able to speed it up further by using `data.table`'s
>`rbindlist` or a similar function as shown here
>https://stackoverflow.com/a/49772719/5861244.
>
>2018-06-10 21:20 GMT+02:00 Christofer Bogaso
><bogaso.christofer using gmail.com>:
>> Using do.call() reduces my calculation time significantly.
>>
>> On Sun, Jun 10, 2018 at 10:45 PM ruipbarradas <ruipbarradas using sapo.pt>
>wrote:
>>
>>> Hello,
>>>
>>> Instead of Reduce try do.call.
>>>
>>> do.call ('rbind', list)
>>>
>>> But with such a long list it will still take time.
>>>
>>> Hope this helps,
>>>
>>> Rui Barradas
>>>
>>>
>>>
>>> Enviado a partir do meu smartphone Samsung Galaxy.
>>> -------- Mensagem original --------
>>> De: Christofer Bogaso <bogaso.christofer using gmail.com>
>>> Data: 10/06/2018 16:33 (GMT+00:00)
>>> Para: r-help <r-help using r-project.org>
>>> Assunto: [R] Efficient manipulation with list object
>>>
>>> Hi,
>>>
>>> I have a list of length 10,000, and each element of that list is a
>matrix
>>> with 3 columns and 2,000 rows.
>>>
>>> Now when I tried to make a Matrix object with that list using
>>> Reduce('rbind', list), my code is taking a considerable amount of
>time.
>>>
>>> Is there any way to implement same above task in more efficient way?
>>>
>>> Thanks,
>>>
>>> [[alternative HTML version deleted]]
>>>
>>> ______________________________________________
>>> R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
>>> 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 using r-project.org mailing list -- To UNSUBSCRIBE and more, see
>> 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 using r-project.org mailing list -- To UNSUBSCRIBE and more, see
>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.

-- 
Sent from my phone. Please excuse my brevity.