Shanshan Chen

• Calculating driving distance between two zip codes based on Google maps

  ``` library(ggmaps) DF = read.csv(“ZipInfo.csv”) ## contains two columns of zip codes, one for origin, the other for destination register_google(key = “…”, write = TRUE)

for some reason, vectorization is not great in mapdist, will return duplicated records if the code below is used

#GoogleDist = mapdist(from = DF$ZIP_start, to = DF$ZIP_end, mode=”driving”)

DF$row.number <- 1:nrow(DF) for (i in 1:205){ a <- mapdist(from = DF$ZIP_origin[i], to = DF$ZIP_destination, mode = “driving”,output = “simple”) a$row.number <- i DF$miles[match(a$row.number, DF$row.number)] <- a$miles DF$hours[match(a$row.number, DF$row.number)] <- a$hours }

- ### Calculating geodistance on a map between two zip codes 

library(data.table) library(geodist) dt_zips <- as.data.table( zip_code_db[, c(“zipcode”, “lng”, “lat”)]) setDT( DF) DF$ZIP = as.character(DF$ZIP) DF$ZIP[1]= “01776”

DF[dt_zips, on = .(ZIP = zipcode), :=(lng_start = lng, lat_start = lat)] DF[dt_zips, on = .(ZIPend = zipcode), :=(lng_end = lng, lat_end = lat)] DF[, distance_metres := geodist::geodist_vec( x1 = lng_start, y1 = lat_start, x2 = lng_end, y2 = lat_end, paired = TRUE, measure = “haversine”)]

DF$Distance_my = DF$distance_metres*0.000621371 ```