Subset rows of a Data/LazyFrame
Usage
# S3 method for class 'RPolarsDataFrame'
slice_tail(.data, ..., n, by = NULL)
# S3 method for class 'RPolarsLazyFrame'
slice_tail(.data, ..., n, by = NULL)
# S3 method for class 'RPolarsDataFrame'
slice_head(.data, ..., n, by = NULL)
# S3 method for class 'RPolarsLazyFrame'
slice_head(.data, ..., n, by = NULL)
# S3 method for class 'RPolarsDataFrame'
slice_sample(.data, ..., n = NULL, prop = NULL, replace = FALSE, by = NULL)Arguments
- .data
A Polars Data/LazyFrame
- ...
Not used.
- n
The number of rows to select from the start or the end of the data. Cannot be used with
prop.- by
Optionally, a selection of columns to group by for just this operation, functioning as an alternative to
group_by(). The group order is not maintained, usegroup_by()if you want more control over it.- prop
Proportion of rows to select. Cannot be used with
n.- replace
Perform the sampling with replacement (
TRUE) or without (FALSE).
Examples
pl_test <- polars::as_polars_df(iris)
slice_head(pl_test, n = 3)
#> shape: (3, 5)
#> ┌──────────────┬─────────────┬──────────────┬─────────────┬─────────┐
#> │ Sepal.Length ┆ Sepal.Width ┆ Petal.Length ┆ Petal.Width ┆ Species │
#> │ --- ┆ --- ┆ --- ┆ --- ┆ --- │
#> │ f64 ┆ f64 ┆ f64 ┆ f64 ┆ cat │
#> ╞══════════════╪═════════════╪══════════════╪═════════════╪═════════╡
#> │ 5.1 ┆ 3.5 ┆ 1.4 ┆ 0.2 ┆ setosa │
#> │ 4.9 ┆ 3.0 ┆ 1.4 ┆ 0.2 ┆ setosa │
#> │ 4.7 ┆ 3.2 ┆ 1.3 ┆ 0.2 ┆ setosa │
#> └──────────────┴─────────────┴──────────────┴─────────────┴─────────┘
slice_tail(pl_test, n = 3)
#> shape: (3, 5)
#> ┌──────────────┬─────────────┬──────────────┬─────────────┬───────────┐
#> │ Sepal.Length ┆ Sepal.Width ┆ Petal.Length ┆ Petal.Width ┆ Species │
#> │ --- ┆ --- ┆ --- ┆ --- ┆ --- │
#> │ f64 ┆ f64 ┆ f64 ┆ f64 ┆ cat │
#> ╞══════════════╪═════════════╪══════════════╪═════════════╪═══════════╡
#> │ 6.5 ┆ 3.0 ┆ 5.2 ┆ 2.0 ┆ virginica │
#> │ 6.2 ┆ 3.4 ┆ 5.4 ┆ 2.3 ┆ virginica │
#> │ 5.9 ┆ 3.0 ┆ 5.1 ┆ 1.8 ┆ virginica │
#> └──────────────┴─────────────┴──────────────┴─────────────┴───────────┘
slice_sample(pl_test, n = 5)
#> shape: (5, 5)
#> ┌──────────────┬─────────────┬──────────────┬─────────────┬────────────┐
#> │ Sepal.Length ┆ Sepal.Width ┆ Petal.Length ┆ Petal.Width ┆ Species │
#> │ --- ┆ --- ┆ --- ┆ --- ┆ --- │
#> │ f64 ┆ f64 ┆ f64 ┆ f64 ┆ cat │
#> ╞══════════════╪═════════════╪══════════════╪═════════════╪════════════╡
#> │ 6.4 ┆ 2.8 ┆ 5.6 ┆ 2.2 ┆ virginica │
#> │ 5.0 ┆ 3.4 ┆ 1.6 ┆ 0.4 ┆ setosa │
#> │ 6.0 ┆ 2.7 ┆ 5.1 ┆ 1.6 ┆ versicolor │
#> │ 6.2 ┆ 2.8 ┆ 4.8 ┆ 1.8 ┆ virginica │
#> │ 5.4 ┆ 3.9 ┆ 1.7 ┆ 0.4 ┆ setosa │
#> └──────────────┴─────────────┴──────────────┴─────────────┴────────────┘
slice_sample(pl_test, prop = 0.1)
#> shape: (15, 5)
#> ┌──────────────┬─────────────┬──────────────┬─────────────┬────────────┐
#> │ Sepal.Length ┆ Sepal.Width ┆ Petal.Length ┆ Petal.Width ┆ Species │
#> │ --- ┆ --- ┆ --- ┆ --- ┆ --- │
#> │ f64 ┆ f64 ┆ f64 ┆ f64 ┆ cat │
#> ╞══════════════╪═════════════╪══════════════╪═════════════╪════════════╡
#> │ 4.7 ┆ 3.2 ┆ 1.6 ┆ 0.2 ┆ setosa │
#> │ 5.6 ┆ 2.9 ┆ 3.6 ┆ 1.3 ┆ versicolor │
#> │ 6.6 ┆ 2.9 ┆ 4.6 ┆ 1.3 ┆ versicolor │
#> │ 5.0 ┆ 3.5 ┆ 1.6 ┆ 0.6 ┆ setosa │
#> │ 5.8 ┆ 4.0 ┆ 1.2 ┆ 0.2 ┆ setosa │
#> │ … ┆ … ┆ … ┆ … ┆ … │
#> │ 5.0 ┆ 3.0 ┆ 1.6 ┆ 0.2 ┆ setosa │
#> │ 7.7 ┆ 2.8 ┆ 6.7 ┆ 2.0 ┆ virginica │
#> │ 6.7 ┆ 3.1 ┆ 4.7 ┆ 1.5 ┆ versicolor │
#> │ 6.7 ┆ 3.1 ┆ 4.4 ┆ 1.4 ┆ versicolor │
#> │ 6.4 ┆ 3.2 ┆ 4.5 ┆ 1.5 ┆ versicolor │
#> └──────────────┴─────────────┴──────────────┴─────────────┴────────────┘