R/munging.R

In amarder/piwikr: Web Analytics for Hackers

#' Compute a table of visitors from a table of actions.
#'
#' @param actions Table of actions.
#' @export
#' @importFrom lubridate floor_date
#'
compute_visitors <- function(actions) {
    visitors <- actions %>%
        group_by_("visitor_id") %>%
        summarise_(day_of_first_visit = "min(day)")

    return(visitors)
}

#' Compute a table of pages from a table of actions.
#'
#' @param actions Table of actions.
#' @param base_url A string like "host.com" with no trailing slash.
#' @export
#'
compute_pages <- function(actions, base_url) {
    pages <- actions %>%
        group_by_("url") %>%
        summarise_(n = ~ length(unique(visitor_id))) %>%
        arrange_(~ desc(n)) %>%
        filter_(~ grepl(paste0("^", base_url), url)) %>%
        mutate_(page = ~ sub(base_url, "", url)) %>%
        select_("page", visitors = "n")

    return(pages)
}

#' Compute a table of days from a table of actions.
#'
#' @param actions Table of actions.
#' @export
#'
compute_days <- function(actions) {
    visitors <- compute_visitors(actions)

    date_range <- function(x) seq(min(x), max(x), by = "days")
    grid <- data.frame(
        day_of_first_visit = date_range(visitors$day_of_first_visit)
    )

    days <- visitors %>%
        group_by_("day_of_first_visit") %>%
        summarise_(new_visitors = "n()") %>%
        right_join(grid, by = "day_of_first_visit") %>%
        mutate_(new_visitors = "ifelse(is.na(new_visitors), 0, new_visitors)")

    return(days)
}

#' Summarise visits by the source of traffic.
#'
#' @param visits Table of visits.
#' @export
#' @importFrom utils head
#'
compute_sources <- function(visits) {
    visitors <- visits %>%
        group_by_("idvisitor") %>%
        mutate_(min_time = ~ min(visit_first_action_time)) %>%
        filter_(~ visit_first_action_time == min_time) %>%
        ungroup()

    sources <- visitors %>%
        mutate_(source = ~ ifelse(referer_type == 1, "(direct)", referer_name)) %>%
        group_by_("source") %>%
        summarise_(visitors = ~ n()) %>%
        arrange_(~ desc(visitors))

    return(sources)
}