slice: Choose rows in a data.table

In tidytable: Tidy Interface to 'data.table'

Choose rows in a data.table

Description

Choose rows in a data.table. Grouped data.tables grab rows within each group.

Usage

slice_head(.df, n = 5, ..., .by = NULL, by = NULL)

slice_tail(.df, n = 5, ..., .by = NULL, by = NULL)

slice_max(.df, order_by, n = 1, ..., with_ties = TRUE, .by = NULL, by = NULL)

slice_min(.df, order_by, n = 1, ..., with_ties = TRUE, .by = NULL, by = NULL)

slice(.df, ..., .by = NULL)

slice_sample(
  .df,
  n,
  prop,
  weight_by = NULL,
  replace = FALSE,
  .by = NULL,
  by = NULL
)

Arguments

.df	A data.frame or data.table
n	Number of rows to grab
...	Integer row values
.by, by	Columns to group by
order_by	Variable to arrange by
with_ties	Should ties be kept together. The default TRUE may return can return multiple rows if they are equal. Use FALSE to ignore ties.
prop	The proportion of rows to select
weight_by	Sampling weights
replace	Should sampling be performed with (TRUE) or without (FALSE, default) replacement

Examples

df <- data.table(
  x = 1:4,
  y = 5:8,
  z = c("a", "a", "a", "b")
)

df %>%
  slice(1:3)

df %>%
  slice(1, 3)

df %>%
  slice(1:2, .by = z)

df %>%
  slice_head(1, .by = z)

df %>%
  slice_tail(1, .by = z)

df %>%
  slice_max(order_by = x, .by = z)

df %>%
  slice_min(order_by = y, .by = z)

tidytable documentation built on Sept. 11, 2024, 8:05 p.m.