Gather every nth element in a list
Description
Gather every nth element in a list
Usage
<Expr>$list$gather_every(n, offset = 0)
Arguments
n
|
Positive integer. |
offset
|
Starting index. |
Value
Expr
Examples
library(polars)
df = pl$DataFrame(
a = list(1:5, 6:8, 9:12),
n = c(2, 1, 3),
offset = c(0, 1, 0)
)
df$with_columns(
gather_every = pl$col("a")$list$gather_every(pl$col("n"), offset = pl$col("offset"))
)
#> shape: (3, 4)
#> ┌───────────────┬─────┬────────┬──────────────┐
#> │ a ┆ n ┆ offset ┆ gather_every │
#> │ --- ┆ --- ┆ --- ┆ --- │
#> │ list[i32] ┆ f64 ┆ f64 ┆ list[i32] │
#> ╞═══════════════╪═════╪════════╪══════════════╡
#> │ [1, 2, … 5] ┆ 2.0 ┆ 0.0 ┆ [1, 3, 5] │
#> │ [6, 7, 8] ┆ 1.0 ┆ 1.0 ┆ [7, 8] │
#> │ [9, 10, … 12] ┆ 3.0 ┆ 0.0 ┆ [9, 12] │
#> └───────────────┴─────┴────────┴──────────────┘