rowwise: Group input by rows

In YTLogos/dplyr: A Grammar of Data Manipulation

Description

rowwise() is used for the results of do() when you create list-variables. It is also useful to support arbitrary complex operations that need to be applied to each row.

Usage

rowwise(data)

Arguments

data	Input data frame.

Details

Currently, rowwise grouping only works with data frames. Its main impact is to allow you to work with list-variables in summarise() and mutate() without having to use [[1]]. This makes summarise() on a rowwise tbl effectively equivalent to [plyr::ldply()].

[[1]: R:[1 [plyr::ldply()]: R:plyr::ldply()

Examples

df <- expand.grid(x = 1:3, y = 3:1)
df %>% rowwise() %>% do(i = seq(.$x, .$y))
.Last.value %>% summarise(n = length(i))

YTLogos/dplyr documentation built on May 20, 2019, 1:44 p.m.