tidytable (version 0.8.0)

slice.: Choose rows in a data.table

Description

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

Usage

slice.(.df, ..., .by = NULL)
slice_head.(.df, n = 5, .by = NULL)
slice_tail.(.df, n = 5, .by = NULL)
slice_max.(.df, order_by, n = 1, .by = NULL)
slice_min.(.df, order_by, n = 1, .by = NULL)
slice_sample.(.df, n, prop, weight_by = NULL, replace = FALSE, .by = NULL)

Arguments

.df

A data.frame or data.table

...

Integer row values

.by

Columns to group by

n

Number of rows to grab

order_by

Variable to arrange by

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)