R/cumulative_miles.R

In jarad/mileageClub: Provides functions and data for the Mary Greeley Medical Center Mileage Club

#' Calculate cumulative miles
#'
#' Calculates the cumulative miles by week.
#' 
#' @param d A \code{data.frame} contain all the cards with day information.
#' @param miles_per_card An integer specifying how many miles a card is worth.
#' @return A \code{data.frame} containing the number of miles run each week and 
#' the cumulative miles per week.
#' @import dplyr
#' @export
#' @examples 
#' \dontrun{
#' read_cards() %>% cumulative_miles
#' }
cumulative_miles = function(d, miles_per_card=5) {
  d %>%
    group_by_(~week) %>%
    summarize_(miles = ~miles_per_card*length(week)) %>%
    arrange_(~week) %>%
    mutate_(cumulative_miles = ~cumsum(miles))
}