dot-make_parameters function

Make parameters for contrast code call

Given a formula, recursively go through the abstract syntax tree and extract the necessary parameters for use_contrasts(). While this method is more involved than extracting from a parsed string representation, I think it handles matrix calls better since it plucks the call right out of the syntax tree.

.make_parameters(
  formula,
  params = list(factor_col = NA, code_by = NA, reference_level = NA, intercept_level =
    NA, drop_trends = NA, labels = NULL, as_is = FALSE),
  env = NULL,
  verbose = TRUE
)

Arguments

• formula: Formula given by user
• params: Parameter accumulator
• env: Environment for the formula, on the first recursion this will be pulled from formula and then passed to subsequent recursions. Needed to check whether a function is actually a function.
• verbose: Logical, default TRUE, whether to show drop_trends warning if used incorrectly

Returns

Named list of parameters that can be evaluated in .process_contrasts()