In constructing or debugging x[i] calls, recommend x[, print(i)], with print being necessary in some cases due to new-ish convenience features of j (example: https://github.com/Rdatatable/data.table/issues/3699#issue-466958803) hm, more simple would be just with(DT, z) -- then there is no need to deal with j being transformed to a list of columns / data.table either
alloc.col (noted by name in the tutorial) to be called setalloccol, soon. I should also check the latest faqs or vignettes to see if guidance has changed
Here are some:
with(DT, z)-- then there is no need to deal withjbeing transformed to a list of columns / data.table either