[R] by class...

[David Winsemius]

On Dec 20, 2013, at 9:45 AM, David Winsemius wrote:

> 
> On Dec 20, 2013, at 9:38 AM, Onur Uncu wrote:
> 
>> I used the by() function on a data.frame to get sums of the data grouped by 2 factors. The function worked however the output is in a class called 'by'. Not familiar with this class. How can I turn the output into a nice table where columns represent values of factor1, row represent values of factor2 and the entries in the table are the sums that were calculated using the by function?
>> 
>> I did some web search which suggested using do.call(rbind, datframe_object) but this command gave the following error:
>> "Second argument must be a list"...
> 
> The output of by() is always a list, so I would have expected:

Or maybe my memories are false.

?by
"This is always a list if simplify is false, otherwise a list or array (see tapply)."

So maybe you need simplify=FALSE

> 
> do.call(rbind, by.object) to have retruned a different error message that what you suggest.
> 
> 
>> 
>> 
>> Thank you.
>> ______________________________________________
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>> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
> 
> David Winsemius
> Alameda, CA, USA
> 
> ______________________________________________
> 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.

David Winsemius
Alameda, CA, USA