What is the exact math used to calculate the maps?
Iterate through each pixel on the map, and for each:Step 1: Locate the n nearest contributions by latitude and longitude (n = 50 for the national maps; a smaller value is used for the regional and local maps until they have enough votes to make 50 work) Step 2: Assign each location a ‘vote strength’ s = 1 / (1 + d ^ 2), where d = the distance from the pixel to the contribution. The scale used for d matters; for the national city map, d = 1 = 60 miles, for the sports maps, d = 1 = 4 miles (this makes them much more sensitive to local fluctuations), the regional maps use d = 1 = 10 miles, and the neighborhood maps use d = 1 = 0.1 miles Step 3: Calculate the cumulative vote tally for the n contributions according to their votes and vote strengths. Because of the vote strengths, votes closer to the pixel will count more. Select the winner Step 4: For the national and regional maps, color the pixel according to the winner.
Iterate through each pixel on the map, and for each: Step 1: Locate the n nearest contributions by latitude and longitude (n = 50 for the national maps; a smaller value is used for the regional and local maps until they have enough votes to make 50 work) Step 2: Assign each location a ‘vote strength’ s = 1 / (1 + d ^ 2), where d = the distance from the pixel to the contribution. The scale used for d matters; for the national city map, d = 1 = 60 miles, for the sports maps, d = 1 = 4 miles (this makes them much more sensitive to local fluctuations), the regional maps use d = 1 = 10 miles, and the neighborhood maps use d = 1 = 0.1 miles Step 3: Calculate the cumulative vote tally for the n contributions according to their votes and vote strengths. Because of the vote strengths, votes closer to the pixel will count more. Select the winner Step 4: For the national and regional maps, color the pixel according to the winner. For the local and sports maps, color the pixel according to the win
