top_n {tidytable}

Select top (or bottom) n rows (by value)

Description

Select the top or bottom entries in each group, ordered by wt.

Usage

top_n(.df, n = 5, wt = NULL, .by = NULL)

Arguments

.df

A data.frame or data.table

n

Number of rows to return

wt

Optional. The variable to use for ordering. If NULL uses the last column in the data.table.

.by

Columns to group by

Examples

df <- data.table(
  x = 1:5,
  y = 6:10,
  z = c(rep("a", 3), rep("b", 2))
)

df %>%
  top_n(2, wt = y)

df %>%
  top_n(2, wt = y, .by = z)