Add a quantile column to a data.table

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Add a quantile column to a data.table

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Last edited Sep 7, 2016

Created on Sep 7, 2016

This example shows how to add a quantile-based categorical column to a data.table in R. The code uses the `data.table` package’s `setDT` and `:=` syntax to create a new `quartile` column by applying `cut` to the `value` column, with breaks defined by `quantile` at 0%, 25%, 50%, 75%, and 100% probabilities. The `right = FALSE` argument assigns values to intervals closed on the left, and labels `1:4` mark the four quartile groups. The result is a modified data.table where each row is assigned a quartile number based on its value’s position in the distribution.

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