tidyft (version 0.4.5)

slice: Subset rows using their positions

Description

`slice()` lets you index rows by their (integer) locations. It allows you to select, remove, and duplicate rows. It is accompanied by a number of helpers for common use cases:

* `slice_head()` and `slice_tail()` select the first or last rows. * `slice_sample()` randomly selects rows. * `slice_min()` and `slice_max()` select rows with highest or lowest values of a variable.

Usage

slice(.data, ...)
slice_head(.data, n)
slice_tail(.data, n)
slice_max(.data, order_by, n, with_ties = TRUE)
slice_min(.data, order_by, n, with_ties = TRUE)
slice_sample(.data, n, replace = FALSE)

Arguments

.data

A data.table

...

Provide either positive values to keep, or negative values to drop. The values provided must be either all positive or all negative.

n

When larger than or equal to 1, the number of rows. When between 0 and 1, the proportion of rows to select.

order_by

Variable or function of variables to order by.

with_ties

Should ties be kept together? The default, `TRUE`, may return more rows than you request. Use `FALSE` to ignore ties, and return the first `n` rows.

replace

Should sampling be performed with (`TRUE`) or without (`FALSE`, the default) replacement.

Value

A data.table

See Also

slice

Examples

# NOT RUN {
a = as.data.table(iris)
slice(a,1,2)
slice(a,2:3)
slice_head(a,5)
slice_head(a,0.1)
slice_tail(a,5)
slice_tail(a,0.1)
slice_max(a,Sepal.Length,10)
slice_max(a,Sepal.Length,10,with_ties = FALSE)
slice_min(a,Sepal.Length,10)
slice_min(a,Sepal.Length,10,with_ties = FALSE)
slice_sample(a,10)
slice_sample(a,0.1)

# }