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Where to inject element(s) to maintain sorting

Source code

Description

Find indices where elements should be inserted to maintain order.

Usage

<Expr>$search_sorted(element)

Arguments

element Element to insert. Can be an Expr or something coercible to an Expr.

Details

This function looks up where to insert element to keep self column sorted. It is assumed the column is already sorted in ascending order (otherwise this leads to wrong results).

Value

Expr

Examples

library(polars)

df = pl$DataFrame(a = c(1, 3, 4, 4, 6))
df

#> shape: (5, 1)
#> ┌─────┐
#> │ a   │
#> │ --- │
#> │ f64 │
#> ╞═════╡
#> │ 1.0 │
#> │ 3.0 │
#> │ 4.0 │
#> │ 4.0 │
#> │ 6.0 │
#> └─────┘

# in which row should 5 be inserted in order to not break the sort?
# (value is 0-indexed)
df$select(
  zero = pl$col("a")$search_sorted(0),
  three = pl$col("a")$search_sorted(3),
  five = pl$col("a")$search_sorted(5)
)

#> shape: (1, 3)
#> ┌──────┬───────┬──────┐
#> │ zero ┆ three ┆ five │
#> │ ---  ┆ ---   ┆ ---  │
#> │ u32  ┆ u32   ┆ u32  │
#> ╞══════╪═══════╪══════╡
#> │ 0    ┆ 1     ┆ 4    │
#> └──────┴───────┴──────┘