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 [email protected] From: [email protected] [mailto:[email protected]] On Behalf Of Farrel Buchinsky Sent: Friday, October 20, 2017 1:14 PM To: [email protected] 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)
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