[datatable-help] Generating data.tables from a j function

[Farrel Buchinsky]

Thank you. That did it.
I would still like to read more. What does one call this? What are the
correct buzzwords to search for. Do you know of any blog posts / articles?

On Fri, Oct 20, 2017 at 2:28 PM Cook, Malcolm <MEC at stowers.org> wrote:

>
>
> Result.dt<-dt[ , list(sd.dtable=dtable(.SD)), by=trichotomous.variable]  #
> untested
>
>
>
> will return a Result.dt with 2 columns: trichotomous.variable and sd.dtable
>
>
>
> The value of Result.dt[1,sd.dtable][[1]] will give the 1st groups dtable
> results
>
>
>
> ~malcolm_cook at stowers.org
>
>
>
> *From:* datatable-help-bounces at lists.r-forge.r-project.org [mailto:
> datatable-help-bounces at lists.r-forge.r-project.org] *On Behalf Of *Farrel
> Buchinsky
> *Sent:* Friday, October 20, 2017 1:14 PM
> *To:* datatable-help at lists.r-forge.r-project.org
> *Subject:* [datatable-help] Generating data.tables from a j function
>
>
>
> I am relatively certain that data.table can handle a function in the J
> position that generates a data.frame or a data.table. However, how does one
> handle the output? Can you please point me to a url that discusses the
> capability?
>
>
>
> For instance, I sometimes use the package dtables to generate descriptive
> statistics. It generates a table for
>
>
>
> So one could go
>
>
>
> library(dtables)
>
> dtable(dt)
>
>
>
> But what if one wanted to get descriptive statistics by a trichotomous
> variable
>
>
>
> dt[ , dtable(.SD), by=trichotomous.variable]
>
>
>
> *I am looking for a general article or blogpost about how to handle
> outputs that are not single numbers or two numbers. *There are functions
> that yield data.tables or lists or specialized objects such a models. Any
> suggestions?
>
>
>
> I know one can simply print the output to the console
>
>
>
> dt[ , print(dtable(.SD)_, by=trichotomous.variable]
>
>
>
> But that does not let me do anything intelligent afterwards.
>
> --
>
> Farrel Buchinsky
>
> (412) 567-7870 (gets me everywhere)
>
-- 
Farrel Buchinsky
(412) 567-7870 (gets me everywhere)
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.r-forge.r-project.org/pipermail/datatable-help/attachments/20171020/06a3aaca/attachment-0001.html>