drake (version 6.1.0)

gather_by: Gather multiple groupings of targets

Description

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

Usage

gather_by(plan, ..., prefix = "target", gather = "list",
  append = TRUE, filter = NULL)

Arguments

plan

workflow plan data frame of prespecified targets

...

Symbols, columns of plan to define target groupings passed to dplyr::group_by(). A gather_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 ....

gather

function used to gather the targets. Should be one of list(...), c(...), rbind(...), or similar.

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.

Value

a workflow plan data frame

See Also

drake_plan, map_plan, reduce_by, reduce_plan, gather_plan, evaluate_plan, expand_plan

Examples

# NOT RUN {
plan <- drake_plan(
  data = get_data(),
  informal_look = inspect_data(data, mu = mu__),
  bayes_model = bayesian_model_fit(data, prior_mu = mu__)
)
plan <- evaluate_plan(plan, rules = list(mu__ = 1:2), trace = TRUE)
plan
gather_by(plan, mu___from, gather = "dplyr::bind_rows")
gather_by(plan, mu___from, append = TRUE)
gather_by(plan, mu___from, append = FALSE)
gather_by(plan, mu__, mu___from, prefix = "x")
gather_by(plan) # Gather everything and append a row.
# You can filter out the informal_look_* targets beforehand
# if you only want the bayes_model_* ones to be gathered.
# The advantage here is that if you also need `append = TRUE`,
# only the bayes_model_* targets will be gathered, but
# the informal_look_* targets will still be included
# in the output.
gather_by(
  plan,
  mu___from,
  append = TRUE,
  filter = mu___from == "bayes_model"
)
# }