drake (version 5.2.1)

evaluate_plan: Use wildcard templating to create a workflow plan data frame from a template data frame.

Description

The commands in workflow plan data frames can have wildcard symbols that can stand for datasets, parameters, function arguments, etc. These wildcards can be evaluated over a set of possible values using evaluate_plan.

Usage

evaluate_plan(plan, rules = NULL, wildcard = NULL, values = NULL,
  expand = TRUE, always_rename = FALSE)

Arguments

plan

workflow plan data frame, similar to one produced by drake_plan()

rules

Named list with wildcards as names and vectors of replacements as values. This is a way to evaluate multiple wildcards at once. When not NULL, rules overrules wildcard and values if not NULL.

wildcard

character scalar denoting a wildcard placeholder

values

vector of values to replace the wildcard in the drake instructions. Will be treated as a character vector. Must be the same length as plan$command if expand is TRUE.

expand

If TRUE, create a new rows in the workflow plan data frame if multiple values are assigned to a single wildcard. If FALSE, each occurrence of the wildcard is replaced with the next entry in the values vector, and the values are recycled.

always_rename

logical. If TRUE, always rename targets according to the wildcard values, regardless of the value of expand. If FALSE, only rename targets if expand is TRUE.

Value

A workflow plan data frame with the wildcards evaluated.

Details

Specify a single wildcard with the wildcard and values arguments. In each command, the text in wildcard will be replaced by each value in values in turn. Specify multiple wildcards with the rules argument, which overrules wildcard and values if not NULL. Here, rules should be a list with wildcards as names and vectors of possible values as list elements.

Examples

# NOT RUN {
# Create the part of the workflow plan for the datasets.
datasets <- drake_plan(
  small = simulate(5),
  large = simulate(50))
# Create a template workflow plan for the analyses.
methods <- drake_plan(
  regression1 = reg1(dataset__),
  regression2 = reg2(dataset__))
# Evaluate the wildcards in the template
# to produce the actual part of the workflow plan
# that encodes the analyses of the datasets.
# Create one analysis for each combination of dataset and method.
evaluate_plan(methods, wildcard = "dataset__",
  values = datasets$target)
# Only choose some combinations of dataset and analysis method.
ans <- evaluate_plan(methods, wildcard = "dataset__",
  values = datasets$target, expand = FALSE)
ans
# For the complete workflow plan, row bind the pieces together.
my_plan <- rbind(datasets, ans)
my_plan
# Workflow plans can have multiple wildcards.
# Each combination of wildcard values will be used
# Except when expand is FALSE.
x <- drake_plan(draws = rnorm(mean = Mean, sd = Sd))
evaluate_plan(x, rules = list(Mean = 1:3, Sd = c(1, 10)))
# }