Geocoding with R: Errors stopping program altogether - r

Question

I have a working program which pulls addresses from a list in Excel and geocodes them using a Google API, but anytime it gets to an address with an apartment, unit, or unfindable address, it stops the program.
I can't get a workable tryCatch routine going inside my loop. :(
Here is the Code:
library("readxl")
library(ggplot2)
library(ggmap)
fileToLoad <- file.choose(new = TRUE)
origAddress <- read_excel(fileToLoad, sheet = "Sheet1")
geocoded <- data.frame(stringsAsFactors = FALSE)
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.csv(origAddress, "geocoded1.csv", row.names=FALSE)
And here is the Error message:
Warning: Geocoding "[removed address]" failed with error:
You must use an API key to authenticate each request to Google Maps Platform APIs. For additional information, please refer to http://g.co/dev/maps-no-account
Error: Can't subset columns that don't exist.
x Location 3 doesn't exist.
i There are only 2 columns.
Run `rlang::last_error()` to see where the error occurred.
In addition: Warning messages:
1: Unknown or uninitialised column: `lon`.
2: Unknown or uninitialised column: `lat`.
3: Unknown or uninitialised column: `geoAddress`.
Now, this is not an API key error because the key works in calls after the error -- and it stops at any address that ends in a number after the street name.
I'm going to be processing batches of thousands of addresses every month and they are not all going to be perfect, so what I need is to be able to skip these bad addresses, put "NA" in the lon/lat columns, and move on.
I'm new to R and can't make a workable error handling routine to handle these types of mistakes. can anyone point me in the right direction? Thanks in advance.

Answer 1

When geocode fails to find an address and output = "latlona", the address field is not returned. You code can be made to work with the following modification.
#
# example data
#
origAddress <- data.frame(addresses = c("white house, Washington",
"white house, # 100, Washington",
"white hose, Washington",
"Washington Apartments, Washington, DC 20001",
"1278 7th st nw, washington, dc 20001") )
#
# simple fix for fatal error
#
for(i in 1:nrow(origAddress))
{
result <- geocode(origAddress$addresses[i], output = "latlona",
source = "google")
origAddress$lon[i] <- result$lon[1]
origAddress$lat[i] <- result$lat[1]
origAddress$geoAddress[i] <- ifelse( is.na(result$lon[1]), NA, result$address[1] )
}
However, you mention that some of your addresses may not be exact. Google's geocoding will try to interpret all address you supply. Sometimes it fails and returns NA but other times its interpretation may not be correct so you should always check geocode results.
A simple method which will catch many errors to set output = "more" in geocode and then examine the values returned in the loctype column. If loctype != "rooftop", you may have a problem. Examing the type column will give you more information. This check isn't complete. To do a more complete check, you could use output = "all" to return all data supplied by google for an address but this requires parsing a moderately complex list. You should read more about the data returned by google geocoding at https://developers.google.com/maps/documentation/geocoding/overview
Also, geocode will take at least tens of minutes at least to return results for thousands of addresses. To minimize the response time, you should supply addresses to geocode as a character vector of addresses. A data frame of results is then returned which you can use to update your origAddress data frame and check for errors as shown below.
#
# Solution should check for wrongly interpreted addresses
#
# see https://developers.google.com/maps/documentation/geocoding/overview
# for more information on fields returned by google geocoding
#
# return all addresses in single call to geocode
#
origAddress <- data.frame(addresses = c("white house, Washington", # identified by name
"white hose, Washington", # misspelling
"Washington Apartments, apt 100, Washington, DC 20001", # identified by name of apartment building
"Washington Apartments, # 100, Washington, DC 20001", # invalid apartment number specification
"1206 7th st nw, washington, dc 20001") ) # address on street but no structure with that address
result <- suppressWarnings(geocode(location = origAddress$addresses,
output = "more",
source = "google") )
origAddress <- cbind(origAddress, result[, c("address", "lon","lat","type", "loctype")])
#
# Addresses which need to be checked
#
check_addresses <- origAddress[ origAddress$loctype != "rooftop" |
is.na(origAddress$loctype), ]