Reduce multiple groupings of targets

Deprecated on 2019-05-16. Use drake_plan() transformations instead. See https://books.ropensci.org/drake/plans.html#large-plans for the details.

Usage

reduce_by(
  plan,
  ...,
  prefix = "target",
  begin = "",
  op = " + ",
  end = "",
  pairwise = TRUE,
  append = TRUE,
  filter = NULL,
  sep = "_"
)

Arguments

plan

Workflow plan data frame of prespecified targets.

...

Symbols, columns of plan to define target groupings. A reduce_plan() call is applied for each grouping. Groupings with all NAs in the selector variables are ignored.

prefix

Character, prefix for naming the new targets. Suffixes are generated from the values of the columns specified in ....

begin

Character, code to place at the beginning of each step in the reduction.

op

Binary operator to apply in the reduction

end

Character, code to place at the end of each step in the reduction.

pairwise

Logical, whether to create multiple new targets, one for each pair/step in the reduction (TRUE), or to do the reduction all in one command.

append

Logical. If TRUE, the output will include the original rows in the plan argument. If FALSE, the output will only include the new targets and commands.

filter

An expression like you would pass to dplyr::filter(). The rows for which filter evaluates to TRUE will be gathered, and the rest will be excluded from gathering. Why not just call dplyr::filter() before gather_by()? Because gather_by(append = TRUE, filter = my_column == "my_value") gathers on some targets while including all the original targets in the output. See the examples for a demonstration.

sep

Character scalar, delimiter for creating the names of new targets.

Value

A workflow plan data frame.

Details

Perform several calls to reduce_plan() based on groupings from columns in the plan, and then row-bind the new targets to the plan.

See also

drake_plan()