Geocoding

If you have a list of places, and you need to find their latitude/longitude coordinates, you have a couple of options.

OPTION 1. The first and more convoluted (but ultimately worthwhile) option is to get a Google API key from the free tier of the Google Cloud Platform, install R and RStudio, and then use this tutorial to work with the "ggmap" R package. I would also recommend watching this YouTube tutorial to fill in some gaps in the first tutorial. 

OPTION 2. Assuming you don't want to learn a new programming language and deal with Google's developer code, here is an alternative:

1. Go to https://www.gpsvisualizer.com/geocoder/ and read about the service (including its limitations and having to potentially double-check/clean up the results).

2. Get an API key from MapQuest. 

   • Go to https://developer.mapquest.com/​.

   • Click on Get Started and complete registration for a free account.

   • Once registered, go to https://developer.mapquest.com/user/me/profile and find your API key (note that it may take up to an hour for the system to process your request and generate your key).

3. ​Copy your API key from MapQuest and paste it into the Your MapQuest AppKey field on the GPS Visualizer website. 

4. Next, open the .csv file that contains your data. For this tutorial, I am using the "city" and "state" columns from Lincoln Mullen's "early-colleges.csv" file.

   • You can download this (or any other file) from GitHub by using DownGit (this link will specifically take you to Mullen's file).

5. Whatever dataset you use, select only the columns that specify the location (can be a single "address" column or a combination of several columns, such as "city," "state," and "country"). Copy those columns and paste them into the Input field in GPS Visualizer.

6. Click Start geocoding and wait for the process to go through all of the fields (more fields = more time). 

7. Once finished, click to select all & copy the results from the Results as text field in GPS Visualizer.

8. In your .csv file, select the first empty cell of a new/empty column and paste the results—you should now have several new columns added to your spreadsheet. Some will be duplicates, so remove those. Most importantly, you should have brand-new "latitude" and "longitude" columns. If that is the case, well done.

9. Go through the list and note any potential discrepancies. Misspellings or places that the tool cannot locate will be assigned wrong coordinates that should be obvious to spot. 

10. Note: in the event that the data you've copied gets pasted into a single column as a string of text, do the following: select the column, in the menu go to Data, select Text to Columns, select Delimited, click Next, select Comma from the Delimited category (and unselect everything else), click Next, and click Finish.