R/robust-lmrob.R

In tidymodels/broom: Convert Statistical Objects into Tidy Tibbles

#' @templateVar class lmRob
#' @template title_desc_tidy
#'
#' @param x A `lmRob` object returned from [robust::lmRob()].
#' @template param_unused_dots
#'
#' @details For tidiers for robust models from the \pkg{MASS} package see
#'   [tidy.rlm()].
#'
#' @examplesIf rlang::is_installed("robust")
#'
#' # load modeling library
#' library(robust)
#'
#' # fit model
#' m <- lmRob(mpg ~ wt, data = mtcars)
#'
#' # summarize model fit with tidiers
#' tidy(m)
#' augment(m)
#' glance(m)
#'
#' @aliases robust_tidiers
#' @export
#' @family robust tidiers
#' @seealso [robust::lmRob()]
tidy.lmRob <- function(x, ...) {
  co <- stats::coef(summary(x))
  ret <- as_tibble(co, rownames = "term")
  names(ret) <- c("term", "estimate", "std.error", "statistic", "p.value")
  ret
}

#' @templateVar class lmRob
#' @template title_desc_augment
#'
#' @inherit tidy.lmRob params examples
#' @template param_data
#' @template param_newdata
#'
#' @details For tidiers for robust models from the \pkg{MASS} package see
#'   [tidy.rlm()].
#'
#' @export
#' @family robust tidiers
#' @seealso [robust::lmRob()]
augment.lmRob <- function(x, data = model.frame(x), newdata = NULL, ...) {
  # NOTES on predict.lmRob:
  #   - there's no na.action = na.pass argument
  #   - predict(x, newdata = NULL) gives an error (i.e. newdata either must
  #     be a dataset or missing)
  #   - predict(x, single_row_df_with_missing_data) returns numeric(0)

  passed_newdata <- !is.null(newdata)
  df <- if (passed_newdata) newdata else data
  df <- as_augment_tibble(df)

  # this is a really ugly way to recover NA predictions
  rows <- split(df, 1:nrow(df))
  preds <- purrr::map(rows, ~ predict(x, newdata = .x))
  no_pred <- purrr::map_lgl(preds, ~ length(.x) == 0)
  preds[no_pred] <- NA

  df$.fitted <- as.numeric(preds)

  resp <- safe_response(x, df)
  if (!is.null(resp)) {
    df$.resid <- df$.fitted - resp
  }
  df
}

#' @templateVar class lmRob
#' @template title_desc_glance
#'
#' @inherit tidy.lmRob params examples
#' @template param_unused_dots
#'
#' @evalRd return_glance(
#'   "r.squared",
#'   "deviance",
#'   "sigma",
#'   "df.residual",
#'   "nobs"
#' )
#'
#' @export
#' @family robust tidiers
#' @seealso [robust::lmRob()]
#'
glance.lmRob <- function(x, ...) {
  as_glance_tibble(
    r.squared = x$r.squared,
    deviance = x$dev,
    sigma = summary(x)$sigma,
    df.residual = x$df.residual,
    nobs = stats::nobs(x),
    na_types = "rrrii"
  )
}