R/refit.R

In fabian-s/stabpath: compute stability selection paths

#' Refit a model on a new dataset
#'
#' This is roughly synonymous to \code{\link[stats]{update}} with
#' \code{update(model, data = new_data)}.
#'
#' @inheritParams get_stability_paths
#' @param new_data the new data
#' @param ... further arguments handed over to methods
#' @return the fitted model object for \code{newdata}
#' @export
refit <- function(model, new_data, ...) {
  UseMethod("refit")
}

#' @describeIn refit method for \code{\link[leaps]{regsubsets}}
#' @importFrom leaps regsubsets
refit.regsubsets <- function(model, new_data, ...) {
  modelcall <- model$call
  if (!is.null(modelcall$weights)) {
    if (is.null(new_data$weights))
      stop("model weights not supplied in 'new_data'")
    modelcall$data <- new_data$data
    modelcall$weights <- new_data$weights
  } else {
    modelcall$data <- new_data
  }
  # use regsubsets-generic instead of regsubsets.formula or other method as
  # regsubsets-methods are not exported by leaps, i.e., not accessible from here:
  do.call(regsubsets, as.list(modelcall[-1]))
}

#' @describeIn refit method for \code{\link[gbm]{gbm}} objects.
refit.gbm <- function(model, new_data, ...) {
  # TODO
}

#' @describeIn refit method for \code{\link[glmnet]{glmnet}} objects
refit.glmnet <- function(model, new_data, ...) {
  # TODO
}