r - How can I make a method to acces a data.table in a structure? -


suppose have this:

dt <- data.table(x = 1:10, y = 1:2) s <- structure(list(dt = dt), class = 'dt_test') 

i want define [ function objects of class dt_test pass on arguments dt. example want able things like

s[, sum(x), = y] s[, z := x + y] 

where [ applied dt. how can make happen?

it can done, i'm not sure should done though. defining method [ sends arguments down data.table pretty straight forward:

`[.dt_test` <- function(x, ...){   x[[1]][...] }  s[, sum(x), = y] 

you have similar generics want supported, example want define [[.

i rather recommend referring data.table inside list directly, majo suggested in comment question. way it's easier understand whats happening in code else might reading (e.g. future you).


Comments

Popular posts from this blog

android - InAppBilling registering BroadcastReceiver in AndroidManifest -

python Tkinter Capturing keyboard events save as one single string -

sql server - Why does Linq-to-SQL add unnecessary COUNT()? -