Sample values from every sub-list

Description

Usage

<Expr>$list$sample(
  n = NULL,
  ...,
  fraction = NULL,
  with_replacement = FALSE,
  shuffle = FALSE,
  seed = NULL
)

Arguments

n Number of items to return. Cannot be used with fraction. Defaults to 1 if fraction is NULL.

… These dots are for future extensions and must be empty.

fraction Fraction of items to return. Cannot be used with n.

with_replacement Allow values to be sampled more than once.

shuffle Shuffle the order of sampled data points.

seed Seed for the random number generator. If NULL (default), a random seed is generated for each sample operation.

Value

A polars expression

Examples

library("polars")

df <- pl$DataFrame(
  values = list(1:3, NA, c(NA, 3L), 5:7),
  n = c(1, 1, 1, 2)
)

df$with_columns(
  sample = pl$col("values")$list$sample(n = pl$col("n"), seed = 1)
)

#> shape: (4, 3)
#> ┌───────────┬─────┬───────────┐
#> │ values    ┆ n   ┆ sample    │
#> │ ---       ┆ --- ┆ ---       │
#> │ list[i32] ┆ f64 ┆ list[i32] │
#> ╞═══════════╪═════╪═══════════╡
#> │ [1, 2, 3] ┆ 1.0 ┆ [3]       │
#> │ [null]    ┆ 1.0 ┆ [null]    │
#> │ [null, 3] ┆ 1.0 ┆ [3]       │
#> │ [5, 6, 7] ┆ 2.0 ┆ [6, 5]    │
#> └───────────┴─────┴───────────┘