Summarise each group to one row

This is a method for the dplyr reframe() generic. It is translated to the j argument of [.data.table.

Usage

# S3 method for class 'dtplyr_step'
reframe(.data, ..., .by = NULL)

Arguments

.data

A lazy_dt().

...

<data-masking>

Name-value pairs of functions. The name will be the name of the variable in the result. The value can be a vector of any length.

Unnamed data frame values add multiple columns from a single expression.

.by

<tidy-select> Optionally, a selection of columns to group by for just this operation, functioning as an alternative to group_by(). For details and examples, see ?dplyr_by.

Examples

library(dplyr, warn.conflicts = FALSE)

dt <- lazy_dt(mtcars)

dt %>%
  reframe(qs = quantile(disp, c(0.25, 0.75)),
          prob = c(0.25, 0.75),
          .by = cyl)
#> Source: local data table [6 x 3]
#> Call:   `_DT32`[, .(qs = quantile(disp, c(0.25, 0.75)), prob = c(0.25, 
#>     0.75)), keyby = .(cyl)]
#> 
#>     cyl    qs  prob
#>   <dbl> <dbl> <dbl>
#> 1     4  78.8  0.25
#> 2     4 121.   0.75
#> 3     6 160    0.25
#> 4     6 196.   0.75
#> 5     8 302.   0.25
#> 6     8 390    0.75
#> 
#> # Use as.data.table()/as.data.frame()/as_tibble() to access results

dt %>%
  group_by(cyl) %>%
  reframe(qs = quantile(disp, c(0.25, 0.75)),
          prob = c(0.25, 0.75))
#> Source: local data table [6 x 3]
#> Call:   `_DT32`[, .(qs = quantile(disp, c(0.25, 0.75)), prob = c(0.25, 
#>     0.75)), keyby = .(cyl)]
#> 
#>     cyl    qs  prob
#>   <dbl> <dbl> <dbl>
#> 1     4  78.8  0.25
#> 2     4 121.   0.75
#> 3     6 160    0.25
#> 4     6 196.   0.75
#> 5     8 302.   0.25
#> 6     8 390    0.75
#> 
#> # Use as.data.table()/as.data.frame()/as_tibble() to access results