group_mutate: group_by and mutate as an atomic action.

In WinVector/seplyr: Improved Standard Evaluation Interfaces for Common Data Manipulation Tasks

group_by and mutate as an atomic action.

Description

Group a data frame by the groupingVars and compute user summaries on this data frame (user summaries specified in ...). Enforces the good dplyr pipeline design principle of keeping group_by and mutate close together. Author: John Mount, Win-Vector LLC.

Usage

group_mutate(d, groupingVars, ..., arrangeTerms = NULL, env = parent.frame())

Arguments

d	data.frame
groupingVars	character vector of column names to group by.
...	list of dplyr::mutate() expressions.
arrangeTerms	character optional vector of quoted column expressions to arrange by.
env	environment to work in.

Value

d mutateed by groups

Examples

group_mutate(datasets::mtcars,
                    c("cyl", "gear"),
                    group_mean_mpg = mean(mpg),
                    group_mean_disp = mean(disp)) %.>%
  head(.)

group_mutate(datasets::mtcars,
                    c("cyl", "gear"),
                    rank = dplyr::row_number(),
                    arrangeTerms = "-disp") %.>%
  head(.)

WinVector/seplyr documentation built on Aug. 26, 2022, 12:01 p.m.