R/ZipRadius.R

In ZipRadius: Creates a Data Frame of US Zip Codes in a Given Radius from a Given US Zip Code

library(geosphere)
library(magrittr)
library(dplyr)
library(rlang)

#' The zipRadius Function
#'
#' @import magrittr
#'
#' @importFrom geosphere distHaversine
#'
#' @importFrom dplyr filter select rename %>%
#'
#' @importFrom utils zip
#'
#' @importFrom rlang .data
#'
#' @param zipcode the reference zip code of which you'd like the list of zip codes within a give radius as character
#'
#' @param radius the distance in miles from the center of the given zip to the center of the other zips as numeric
#'
#' @examples zipRadius("30316", 10)
#'
#'@export
zipRadius <- function(zipcode, radius){
  # Get the lat/lon of the reference zip
  refPoint <- dplyr::filter(zipList, .data$zip == zipcode) %>%
    dplyr::select(.data$latitude, .data$longitude) %>%
    dplyr::rename(refLat = .data$latitude, refLon = .data$longitude)

  # Add the lat/lon of the ref zip to the zipList
  zipList <- cbind(zipList, refPoint)

  # Radius of Earth in miles to adjust for km
  r = 3959

  # Creating Table of the coordinates. Makes it easy to calc distance
  Points1 <- cbind(zipList$longitude,zipList$latitude)
  Points2 <- cbind(zipList$refLon,zipList$refLat)
  distance <- distHaversine(Points1,Points2,r)

  # Adding distance back on to the original zipList
  zipList$Distance <- round(distance, 2)

  # Remove reference lat/lon and filter down to below selected radius
  zipList <- dplyr::select(zipList, -.data$refLat, -.data$refLon) %>%
    dplyr::filter(.data$Distance < radius)

  return(zipList)
  }

#' getStates returns the list of states which have zip codes which fall in a specified radius in lower case format for use in choroplethrZip
#'
#' @param zipcode the reference zip code of which you'd like the list of zip codes within a give radius as character
#'
#' @param radius the distance in miles from the center of the given zip to the center of the other zips as numeric
#'
#' @examples getStates("30316", 10)
#'
#'@export
getStates <- function(zipcode, radius){
  data <- zipRadius(zipcode, radius)
  stateTable <- as.data.frame(cbind(datasets::state.abb, tolower(datasets::state.name)))
  zipStates <- unique(data$state)
  States <- as.character(stateTable[which(stateTable$V1 %in% zipStates),2])
  States
}

#' getZipPop returns a data frame of zipcodes and their population where the zip codes fall within a given radius for use in choroplethrZip
#'
#' @importFrom dplyr data_frame inner_join
#'
#' @param zipcode the reference zip code of which you'd like the list of zip codes within a give radius as character
#'
#' @param radius the distance in miles from the center of the given zip to the center of the other zips as numeric
#'
#' @examples getStates("30316", 10)
#'
#'@export
getZipPop <- function(zipcode, radius){
  data <- zipRadius(zipcode, radius)
  zips <- suppressWarnings(suppressMessages((dplyr::data_frame(region = data[,1]) %>%
    dplyr::inner_join(df_pop_zip))))
  zips
  }

#' getZips returns the list of zip codes as a character vector which have zip codes which fall in a specified radius in lower case format for use in choroplethrZip
#'
#' @param zipcode the reference zip code of which you'd like the list of zip codes within a give radius as character
#'
#' @param radius the distance in miles from the center of the given zip to the center of the other zips as numeric
#'
#' @examples getZips("30316", 10)
#'
#'@export
getZips <- function(zipcode, radius){
  data <- zipRadius(zipcode, radius)
  zips <- data$zip
  zips
}