CODEWITHSUNDEEP
rgeocodingggmap
tangerine7199
tangerine7199

Reputation: 489

R-Geocoding with Address

I have 32K lines of addresses for which I have to find long/latitude values.

I'm using the code found here. I'm so very thankful for this person to creating it but I have a question:

I'd like to edit it so that if the loop runs into an issue with the current row's address, it simply states NA in the Lat/Long fields and moves to the next one. Does anyone know how that may be accomplished? The code is below:

# Geocoding a csv column of "addresses" in R

#load ggmap
library(ggmap)

# Select the file from the file chooser
fileToLoad <- file.choose(new = TRUE)

# Read in the CSV data and store it in a variable 
origAddress <- read.csv(fileToLoad, stringsAsFactors = FALSE)

# Initialize the data frame
geocoded <- data.frame(stringsAsFactors = FALSE)

# Loop through the addresses to get the latitude and longitude of each address and add it to the
# origAddress data frame in new columns lat and lon
for(i in 1:nrow(origAddress))
{
  # Print("Working...")
  result <- geocode(origAddress$addresses[i], output = "latlona", source = "google")
  origAddress$lon[i] <- as.numeric(result[1])
  origAddress$lat[i] <- as.numeric(result[2])
  origAddress$geoAddress[i] <- as.character(result[3])
}
# Write a CSV file containing origAddress to the working directory
write.csv(origAddress, "geocoded.csv", row.names=FALSE)

Upvotes: 1

Views: 4732

Answers (1)

Ben Fasoli
Ben Fasoli

Reputation: 526

You can use tryCatch() to isolate the geocode warning and return a data.frame with the same structure (lon, lat, address) as geocode() would return.

Your code would then be

# Geocoding a csv column of "addresses" in R

# load ggmap
library(ggmap)

# Select the file from the file chooser
fileToLoad <- file.choose(new = TRUE)

# Read in the CSV data and store it in a variable 
origAddress <- read.csv(fileToLoad, stringsAsFactors = FALSE)

# Loop through the addresses to get the latitude and longitude of each address and add it to the
# origAddress data frame in new columns lat and lon
for(i in 1:nrow(origAddress)) {
  result <- tryCatch(geocode(origAddress$addresses[i], output = "latlona", source = "google"),
                     warning = function(w) data.frame(lon = NA, lat = NA, address = NA))
  origAddress$lon[i] <- as.numeric(result[1])
  origAddress$lat[i] <- as.numeric(result[2])
  origAddress$geoAddress[i] <- as.character(result[3])
}
# Write a CSV file containing origAddress to the working directory
write.csv(origAddress, "geocoded.csv", row.names=FALSE)

Alternatively, you can do this faster and more cleanly without the loop and error checking. However, without a reproducible example of your data there is no way to know if this will retain all of the information you need.

# Substituted for for loop
result <- geocode(origAddress$addresses, output = "latlona", source = "google")
origAddress <- cbind(origAddress$addresses, result)

Upvotes: 5

Related Questions