broom.helpers (version 1.0.0)

tidy_add_reference_rows: Add references rows for categorical variables

Description

For categorical variables with a treatment contrast (stats::contr.treatment()), a SAS contrast (stats::contr.SAS()) or a sum contrast (stats::contr.sum()), add a reference row.

Usage

tidy_add_reference_rows(x, model = tidy_get_model(x), quiet = FALSE)

Arguments

x

a tidy tibble

model

the corresponding model, if not attached to x

quiet

logical argument whether broom.helpers should return an error when requested output cannot be generated. Default is FALSE

Details

The added reference_row column will be equal to:

• TRUE for a reference row;

• FALSE for a normal row of a variable with a reference row;

• NA for variables without a reference row.

If the contrasts column is not yet available in x, tidy_add_contrasts() will be automatically applied.

tidy_add_reference_rows() will not populate the label of the reference term. It is therefore better to apply tidy_add_term_labels() after tidy_add_reference_rows() rather than before.

See Also

Other tidy_helpers: tidy_add_contrasts(), tidy_add_estimate_to_reference_rows(), tidy_add_header_rows(), tidy_add_term_labels(), tidy_add_variable_labels(), tidy_attach_model(), tidy_identify_variables(), tidy_plus_plus(), tidy_remove_intercept()

Examples

# NOT RUN {
df <- Titanic %>%
  dplyr::as_tibble() %>%
  dplyr::mutate(Survived = factor(Survived, c("No", "Yes")))

df %>%
  glm(
    Survived ~ Class + Age + Sex,
    data = ., weights = .$n, family = binomial,
    contrasts = list(Age = contr.sum, Class = "contr.SAS")
  ) %>%
  tidy_and_attach() %>%
  tidy_add_reference_rows()

if (requireNamespace("gtsummary")) {
  glm(
    response ~ stage + grade * trt,
    gtsummary::trial,
    family = binomial,
    contrasts = list(
      stage = contr.treatment(4, base = 3),
      grade = contr.treatment(3, base = 2),
      trt = contr.treatment(2, base = 2)
    )
  ) %>%
    tidy_and_attach() %>%
    tidy_add_reference_rows()
}
# }