R/leaflet_map.R

In Nilesh1978/eqv: Visualization of the eqarthquake data

#' Leaflet map of earthquakes
#'
#' This function creates a \code{leaflet} map of selected earthquakes based on
#' input NOAA earthquake cleaned data.
#'
#' @param data A data frame containing cleaned NOAA earthquake data
#' @param annot_col A character. The name of the column in the data that should
#' be used as descriptor.
#'
#' @return A leaflet map with earthquakes and annotations.
#' @export
#'
#' @importFrom leaflet leaflet addTiles addCircleMarkers
#' @importFrom magrittr %>%
#'
#' @examples
#' \dontrun{
#' eq_map(data, annot_col = "LOCATION_NAME")
#' }
eq_map <- function(data, annot_col) {

  m <- leaflet::leaflet() %>%
    leaflet::addTiles() %>%
    leaflet::addCircleMarkers(lng = data$LONGITUDE, lat = data$LATITUDE,
                              radius = data$EQ_PRIMARY, weight = 1,
                              popup = data[[annot_col]])

  m
}


#' Creates a label for leaflet map
#'
#' This function creates a label for the \code{leaflet} map based on location
#' name, magnitude and casualties from NOAA earthquake data
#'
#' @param data A data frame containing cleaned NOAA earthquake data
#'
#' @return A character vector with labels
#'
#' @details The input \code{data.frame} needs to include columns LOCATION_NAME,
#' EQ_PRIMARY and TOTAL_DEATHS with the earthquake location, magintude and
#' total casualties respectively.
#'
#' @export
#'
#' @examples
#' \dontrun{
#' eq_create_label(data)
#' }
eq_create_label <- function(data) {
  popup_text <- with(data, {
    part1 <- ifelse(is.na(LOCATION_NAME), "",
                    paste("<strong>Location:</strong>",
                          LOCATION_NAME))
    part2 <- ifelse(is.na(EQ_PRIMARY), "",
                    paste("<br><strong>Magnitude</strong>",
                          EQ_PRIMARY))
    part3 <- ifelse(is.na(TOTAL_DEATHS), "",
                    paste("<br><strong>Total deaths:</strong>",
                          TOTAL_DEATHS))
    paste0(part1, part2, part3)
  })
}