R/augment-hai-fourier.R

In healthyR.ai: The Machine Learning and AI Modeling Companion to 'healthyR'

#' Augment Function Fourier
#'
#' @family Augment Function
#'
#' @author Steven P. Sanderson II, MPH
#'
#' @description
#' Takes a numeric vector(s) or date and will return a tibble of one of the following:
#' -  "sin"
#' -  "cos"
#' -  "sincos"
#' -  c("sin","cos","sincos")
#'
#' @details
#' Takes a numeric vector or date and will return a vector of one of the following:
#' -  "sin"
#' -  "cos"
#' -  "sincos"
#' -  c("sin","cos","sincos")
#'
#' This function is intended to be used on its own in order to add columns to a
#' tibble.
#'
#' @param .data The data being passed that will be augmented by the function.
#' @param .value This is passed [rlang::enquo()] to capture the vectors you want
#' to augment.
#' @param .period The number of observations that complete a cycle
#' @param .order The fourier term order
#' @param .names The default is "auto"
#' @param .scale_type A character of one of the following: "sin","cos", or sincos" All
#' can be passed by setting the param equal to c("sin","cos","sincos")
#'
#' @examples
#' suppressPackageStartupMessages(library(dplyr))
#'
#' len_out <- 10
#' by_unit <- "month"
#' start_date <- as.Date("2021-01-01")
#'
#' data_tbl <- tibble(
#'   date_col = seq.Date(from = start_date, length.out = len_out, by = by_unit),
#'   a = rnorm(len_out),
#'   b = runif(len_out)
#' )
#'
#' hai_fourier_augment(data_tbl, b, .period = 12, .order = 1, .scale_type = "sin")
#' hai_fourier_augment(data_tbl, b, .period = 12, .order = 1, .scale_type = "cos")
#'
#' @return
#' A augmented tibble
#'
#' @export
#

hai_fourier_augment <- function(.data,
                                .value,
                                .period,
                                .order,
                                .names = "auto",
                                .scale_type = c("sin", "cos", "sincos")) {
  column_expr <- rlang::enquo(.value)


  if (rlang::quo_is_missing(column_expr)) stop(call. = FALSE, "fourier_augment(.value) is missing.")

  col_nms <- names(tidyselect::eval_select(rlang::enquo(.value), .data))

  make_call <- function(col, period, order, scale_type) {
    rlang::call2(
      "hai_fourier_vec",
      .x = rlang::sym(col),
      .period = period,
      .order = order,
      .scale_type = scale_type,
      .ns = "healthyR.ai"
    )
  }

  grid <- expand.grid(
    col = col_nms,
    period = .period,
    order = .order,
    scale_type = .scale_type,
    stringsAsFactors = FALSE
  )

  calls <- purrr::pmap(.l = list(grid$col, grid$period, grid$order, grid$scale_type), make_call)

  if (any(.names == "auto")) {
    newname <- paste0("fourier_", grid$col, "_", grid$scale_type)
  } else {
    newname <- as.list(.names)
  }

  calls <- purrr::set_names(calls, newname)

  ret <- tibble::as_tibble(dplyr::mutate(.data, !!!calls))

  return(ret)
}