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Mapping with R

Converting Addresses to Coordinates (01_09)

Transcript

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Your Turn

Open the 01_09 project. In the your-turn.R file:

Convert the addresses in the “International Addresses” worksheet into coordinates and visualise them.

  • Import the “International Addresses” worksheet

  • Re-use the mutate(across(...)) code to remove NA values

  • Combine together address_line_1, address_line_2, address_line_3 into full_address

  • Use geocode() to convert the addresses into coordinates

  • Visualise the locations with mapview

Learn More

This video introduces two packages for forward geocoding, which I’d like to summarise again here:

ggmap uses the Google Maps Geocoding API which is extremely well regarded and considered an industry standard. However, to register for the API you must provide your credit card details to Google. As of late 2020 users are provided with $300 free credit per month, however this could change in the future. Instructions for setting up your Google Cloud Platform account can be found on the ggmap package website.

tidygeocoder provides access to four different geocoding API via the method argument:

  • “census” is the default and connects to the free to use US Census Geocoder but is only useful for addresses in the US

  • “geocodio” uses the commercial geocoding service Geocodio that covers only the US and Canada. A free tier is available and you do not need to provide your billing details for this type of account.

  • “iq” uses the international commercial geocoding service LocationIQ. A free tier is available and you do not need to provide your billing details for this type of account. 

It’s important to remember that there is (unfortunately) not an international standard for formatting street addresses. In general, the more specific a query the more likely an API will return an accurate set of coordinates.

Have any questions? Put them below and we will help you out!

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Kristina Bratkova

Kristina Bratkova • March 2, 2022

Hello, I was wondering whether the order of arguments in geocode() function matters (i.e. whether we specify street= street_address, city = city, postalcode = postal_code, in this order or different one)? I was also wondering whether adding more columns to geocode() that have many NAs like state=region may prevent from finding the addresses (for example, iq method found all 11 addresses each time but without the method specified, geocode found only 4 addresses with state=region argument (plus all other column as in the example) but excluding this argument geocode found 9 addresses; this question may be related to the first one perhaps?

Kristina Bratkova

Kristina Bratkova • March 4, 2022

Hi David and Charlie,

many thanks for your replies. Charlie, yes correct, the 'osm' (default) method found 9 addresses out of 11 but only 4 with state=region argument (as it has fussy NAs as you explain). 'iq' method found all 11 in both instances.

Great course so far!

Jeremy Danz

Jeremy Danz • February 12, 2023

Are there regional differences or any other settings that would influence which values are returned for the fragmented address information we're starting with? Following this code exactly never found coordinates for the American University in Cairo, for example, and the map I've produced seems to think the Harbin University of Science and Technology is in Italy!

In the instructions for the "Your Turn" section, it mentions combining three lines of the address into full_address, and using mutate(across(...)) to remove NA values, but these steps don't seem to be mentioned in the solutions video or the solutions code chunk. Did I miss something there?

Thanks!! The course is awesome, I'm having a lot of fun :)

Course Content

34 Lessons