Rdatatable / Rdatatable/data.table
[R-Forge #2605] add filtering option to fread so it can load less than all rows
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feature request
fread
top request
- Dominant language
- R
- Stars
- 3.9k
- Forks
- 1.1k
- Avg merge
- 14h 4m
- Merged PRs (30d)
- 4
Description
Submitted by: stat quant; Assigned to: Nobody; R-Forge link
Discussed in data.table list.
fread(input, chunk.nrows=10000, chunk.filter = <anything acceptable to i of DT[i]>), that could be grep() or any expression of column names.
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Start by reading the fread entry point and the linked discussion about chunk.nrows and chunk.filter. Determine how an i-like filter or grep expression should be specified and evaluated during loading. Done means fread can load fewer than all rows using the requested filtering option, with its behavior documented and verified.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- r
- Domain
- data
- Issue type
- Feature
- Difficulty
- 5/5
- Estimated time
- Over a week
- Activity status
- Stale
- Clarity
- Needs clarification
- Newbie friendliness
- 25/100