question | warnings with joins

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Assessment

Difficulty
4/5
Estimated time
3-5 days
Newbie friendliness
25/100
Issue type
Bug
Clarity
Needs clarification
Activity status
Stale
Tech stack
r
Domain
data

Research direction

Start by running the two R/data.table examples in the issue and then construct a reproducible case for each warning. The report names no files or tests; done would require identifying the join or ifelse conditions that trigger the warnings and documenting the correct handling or expected behavior.

Written by the indexing model from the issue text.

Description

joins

Hi,
may I please ask you

1
I used to experience warnings like:
Coerced 'integer' RHS to 'logical' to match the column's type. Either change the target column to 'integer' first (by creating a new 'integer' vector length 4277 (nrows of entire table) and assign that; i.e. 'replace' column), or coerce RHS to 'logical' (e.g. 1L, NA_[real|integer]_, as.*, etc) to make your intent clear and for speed. Or, set the column type correctly up front when you create the table and stick to it, please.

in the joins like:

a = data.table(id1 = c(1,2,3), id2 = c(1,2,3), field = c(1,2,3))
b = data.table(id1 = c(1,2,3), id2 = c(11,22,33), field = c(1,2,3))
a[b, field := i.field, on=.(id1 = id2)]

There is no ifelse condition
In this small sample there is no such a warning

I cannot always reproduce but maybe you can advice - what is the best way to prevent this?
I did the check that nrow(b) > 0 but it doesnt help a lot

2
and the second question with ifelse
similar problem in terms of reproducing
but the idea is:

a = data.table(id1 = c(1,2,3), id2 = c(1,2,3), field = c(1,2,3))
b = data.table(id1 = c(1,2,3), id2 = c(11,22,33), field = c(1,2,3))
a[b, field := ifelse(id2 > i.id2, i.field, field), on=.(id1)]

as I understand sometimes there is NA condition inside of ifelse and there is warning as well - is there a way to handle it somehow properly? I am not sure its the best idea to write the long prejoin conditions like if (nrow(a[b, on=.(id1=id2)) > 0) or smth

Thank you

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