R/index-helpers.R

In brolgar: Browse Over Longitudinal Data Graphically and Analytically in R

#' Index summaries 
#' 
#' These functions check if the index is regular (`index_regular()`), and
#'     summarise the index variable (`index_summary()`). This can be useful 
#'     to check your index variables.
#'
#' @param .data data.frame or tsibble
#' @param index the proposed index variable
#' @param ... extra arguments
#' @name index_summary
#'
#' @return logical  TRUE means it is regular, FALSE means not
#'
#' @examples
#' # a tsibble
#' index_regular(heights)
#' 
#' # some data frames
#' index_regular(pisa, year)
#' index_regular(airquality, Month)
#' 
#' # a tsibble
#' index_summary(heights)
#' # some data frames
#' index_summary(pisa, year)
#' index_summary(airquality, Month)
#' index_summary(airquality, Day)
#' @export
index_regular <- function(.data, ...){
  UseMethod("index_regular")
}


#' @rdname index_summary
#' @export
index_regular.tbl_ts <- function(.data, ...){
  
  .data %>% 
    dplyr::pull(tsibble::index(.)) %>% 
    unique() %>% 
    sort() %>% 
    diff() %>% 
    unvarying()
  
}

#' @rdname index_summary
#' @export
index_regular.data.frame <- function(.data, index, ...){
  
  .data %>% 
    dplyr::pull( {{index }} ) %>% 
    unique() %>% 
    sort() %>% 
    diff() %>% 
    unvarying() 
}

#' @rdname index_summary
#' @export
index_summary <- function(.data, ...){
  UseMethod("index_summary")
}


#' @rdname index_summary
#' @export
index_summary.tbl_ts <- function(.data, ...){
  .data %>% 
    dplyr::pull(tsibble::index(.)) %>% 
    unique() %>% 
    summary()
}

#' @rdname index_summary
#' @export
index_summary.data.frame <- function(.data, index, ...){
  .data %>% 
    dplyr::pull( {{index}} ) %>% 
    unique() %>% 
    summary()
}