Get the index of the maximal value in an array

Source code

Description

Get the index of the maximal value in an array

Usage

<Expr>$arr$arg_max()

Value

Expr

Examples

library("polars")

df = pl$DataFrame(
  values = list(1:2, 2:1),
  schema = list(values = pl$Array(pl$Int32, 2))
)
df$with_columns(
  arg_max = pl$col("values")$arr$arg_max()
)

#> shape: (2, 2)
#> ┌───────────────┬─────────┐
#> │ values        ┆ arg_max │
#> │ ---           ┆ ---     │
#> │ array[i32, 2] ┆ u32     │
#> ╞═══════════════╪═════════╡
#> │ [1, 2]        ┆ 1       │
#> │ [2, 1]        ┆ 0       │
#> └───────────────┴─────────┘