Compute the sign

Description

This returns -1 if x is lower than 0, 0 if x == 0, and 1 if x is greater than 0.

Usage

<Expr>$sign()

Value

A polars expression

Examples

library("polars")

df <- pl$DataFrame(a = c(-9, 0, 0, 4, NA))
df$with_columns(sign = pl$col("a")$sign())

#> shape: (5, 2)
#> ┌──────┬──────┐
#> │ a    ┆ sign │
#> │ ---  ┆ ---  │
#> │ f64  ┆ f64  │
#> ╞══════╪══════╡
#> │ -9.0 ┆ -1.0 │
#> │ 0.0  ┆ 0.0  │
#> │ 0.0  ┆ 0.0  │
#> │ 4.0  ┆ 1.0  │
#> │ null ┆ null │
#> └──────┴──────┘