Skip to content

Set Ordering

Source code

Description

Determine how this categorical series should be sorted.

Usage

<Expr>$cat$set_ordering(ordering)

Arguments

ordering string either ‘physical’ or ‘lexical’
  • ‘physical’ -\> Use the physical representation of the categories to determine the order (default).
  • ‘lexical’ -\> Use the string values to determine the ordering.

Value

bool: TRUE if equal

Examples

library(polars)

df = pl$DataFrame(
  cats = factor(c("z", "z", "k", "a", "b")),
  vals = c(3, 1, 2, 2, 3)
)

# sort by the string value of categories
df$with_columns(
  pl$col("cats")$cat$set_ordering("lexical")
)$sort("cats", "vals")

#> shape: (5, 2)
#> ┌──────┬──────┐
#> │ cats ┆ vals │
#> │ ---  ┆ ---  │
#> │ cat  ┆ f64  │
#> ╞══════╪══════╡
#> │ a    ┆ 2.0  │
#> │ b    ┆ 3.0  │
#> │ k    ┆ 2.0  │
#> │ z    ┆ 1.0  │
#> │ z    ┆ 3.0  │
#> └──────┴──────┘

# sort by the underlying value of categories
df$with_columns(
  pl$col("cats")$cat$set_ordering("physical")
)$sort("cats", "vals")

#> shape: (5, 2)
#> ┌──────┬──────┐
#> │ cats ┆ vals │
#> │ ---  ┆ ---  │
#> │ cat  ┆ f64  │
#> ╞══════╪══════╡
#> │ z    ┆ 1.0  │
#> │ z    ┆ 3.0  │
#> │ k    ┆ 2.0  │
#> │ a    ┆ 2.0  │
#> │ b    ┆ 3.0  │
#> └──────┴──────┘