gwhich.max: GForce which min/max
@ben-schwen is already working on this.
Since Apr 28, 2026.
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Description
Marked as TODO in https://github.com/Rdatatable/data.table/blob/7db13b99f6029d343f7127a8f7971bdf2e5fec0d/src/gsumm.c#L1021
I wonder if that could be used to optimize following queries "getting the latest version of data by group":
x[, .SD[timestamp_col == max(timestamp_col)], by = c(grouping_cols)]
base R which.max returns only first index, not all matching.
Considering above query returns 1+ rows for each group, it should be easier to implement now after having https://github.com/Rdatatable/data.table/pull/5089
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