R/Map_data.R

In RG9303/ProjectRGCapstone:

#' Map earthquakes.
#'
#' Produces a map of earthquake epicenters (LATITUDE/LONGITUDE) and annotates
#' each point with a popup window containing annotation data stored in a column
#' of the data frame.
#'
#' @param df Data frame containing at least LONGITUDE, LATITUDE, and EQ_PRIMARY columns.
#'
#' @param annot_col Character string with the name of the column to use for the popup windows.
#'
#' @examples
#' \dontrun{
#' eq_map(earthquakes, annot_col = "DATE")
#'}
#' @note
#' See \code{\link{eq_create_label}} for another example.
#'
#' @import leaflet
#'
#' @export
#'
eq_map <- function (df, annot_col) {
  the_map <- leaflet::leaflet()
  the_map <- leaflet::addTiles(the_map)
  leaflet::addCircleMarkers(the_map, data = df, lng = ~LONGITUDE,
                            lat = ~LATITUDE, radius = ~EQ_PRIMARY, weight = 1, popup = df[[annot_col]])
}




#' Create HTML labels for earthquakes with location, magnitude, and total deaths for earthquake data.
#'
#' @param df Data frame containing at least LOCATION_NAME, EQ_PRIMARY, and TOTAL_DEATHS columns.
#'
#' @return Character string with the HTML label.
#'
#' @examples
#' \dontrun{
#' # This can be used with \code{\link{eq_map}} as follows:
#' library(dplyr)
#'
#' earthquakes %>%
#'   dplyr::mutate(popup_text = eq_create_label(.)) %>%
#'   eq_map(annot_col = "popup_text")
#'}
#' @export
#'
eq_create_label <- function (df) {
  paste(sep = "<br/>", paste("<b>Location:</b>",
                             df$LOCATION_NAME), paste("<b>Magnitude:</b>", df$EQ_PRIMARY),
        paste("<b>Total deaths:</b>", df$TOTAL_DEATHS))
}