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Graduated colors by frequency of category and date span?

Question asked by khowaga on Aug 1, 2017
Latest reply on Jan 11, 2018 by MidnightYell2003

I am creating a map of various disease outbreaks in Egypt during World War I.

 

I have:

 

1) a table containing a list of 800+ outbreaks - formerly a spreadsheet - which includes the disease, the date the outbreak was reported, the name of the specific location, its latitude and longitude, and each entry also contains the level 1 and level 2 administrative divisions by name, as well as their a two digit code (there's diacritics - thought numbers would go down easier).

 

2) Two feature layers containing polygons that I drew - one containing the level 1 administrative divisions and one containing the and level 2 (the polygon attributes including the names and the two digit identifier for each).

 

The sticky widget here is that the boundaries have changed in the past 100 years, and I wound up having to trace a map out of the 1917 census to get the level 1 and 2 administrative divisions for the time. It's close, but about 500 meters - 2 kilometers off from actual accuracy in places. In other words, this is why I'm reluctant to run a report based on the geolocation and want to try to do it based on the name/identifier since I got those directly from the source data and know they're correct.

 

What I want to be able to do is shade the administrative divisions according to the number of outbreaks of a specific disease in a given year. There's a one-to-many relationship on the administrative subdivisions-to-outbreaks, and after two days of trying to figure this out I've decided to run up the white flag and ask for help from others who know what they're doing better than I.

 

I literally started learning how to work with ARCmap a month ago for this project, and I've gotten to the point where I can look at my points on the map (including the ones I coded wrong and wound up on Cyprus - oops), and I created a frequency layer that gave me the sum total of *all* records for each subdivision, but I can't figure out how to break this down further by disease type and date span.

 

Please use small words - I'm new at this! Thanks!

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