Convert LHS := lapply(...) to a set(...) for loop internally?
Nobody has claimed this yet.
Assessment
- Difficulty
- 5/5
- Estimated time
- Over a week
- Newbie friendliness
- 25/100
- Issue type
- Feature
- Clarity
- Needs clarification
- Activity status
- Stale
- Tech stack
- r
- Domain
- data, performance
Research direction
Start by reading the linked discussion in #1441 and the examples involving lapply(.SD, ...) across hundreds or thousands of columns. Investigate how grouped assignment currently materializes lapply output and whether an internal set(...) loop is feasible without affecting speed. Done means a clear implementation direction and evidence about memory and performance trade-offs.
Written by the indexing model from the issue text.
Description
Would this be possible/advisable even in grouping settings?
I have in mind doing lapply(.SD, ...) for .SD of 100s or 1000s of columns -- fundamentally, IINM, we have to store the output in memory first before assigning, so that the for loop approach would be much more memory-efficient.
Ideally it'd be done without any speed impact. Any considerations I'm missing?
another issue asks for that, also mentioning support for doing that by group, see #1441.
- Dominant language
- R
- Stars
- 3.9k
- Forks
- 1.1k
- Avg merge
- 14h 4m
- Merged PRs (30d)
- 4
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