I'm a new user, and I've been experimenting with Tableau Public (version 10.4.2) as a way to create more compelling charts, graphs, and visualizations for my job - working with fundraising/donation data for an educational institution.
One project my boss has asked me to work on is creating a heat map that shows all of our constituents in the US and color-codes regions based on how many people have given to the college at least once in their lives. Using latitude/longitude coordinates that we generated for each address, I've created the following point maps:
The map listed as "yes/no" under metadata just color-codes based on whether anyone at that geocode has given a gift in the past, and the map listed as "gradient" color-codes based on how many gifts anyone at that geocode has given. Both of these are just using a small sample of the data, about 100 records. (I'm not entirely sure whether the original data will be available/visible by downloading the workbook, so just to be on the safe side, I've attached the original Excel file after making sure to remove any confidential data.)
These maps are a good start, but what I'm trying to work towards is creating a filled heat map, such as in this link:
Does anybody have any recommendations for how to go about doing this? I tried to turn the latitude/longitude pairs into a single geographic dimension called "Combined Geocode" (in the hope that would allow me to use both map types in the "Show Me" bar), but Tableau reads that as a string when I attach the data, and I'm not quite sure what kind of geographic dimension I should tell Tableau to use it as.
Now that I think about it, using the city name or ZIP code as a geographic dimension would probably work equally well... but, since my department and I went to the trouble of converting so many addresses to geocodes (30,000+ records), I'd like to at least try to find a use for them.