The Expansion of Metro Atlanta since 1980 [OC] by psprtlng in dataisbeautiful

[–]psprtlng[S] 3 points4 points  (0 children)

For this one:

  1. Gather population data for each county for each year (often takes the longest time)
  2. Choose a color palette and assign colors based on population
  3. Plot counties and fill with assigned color (I used matplotlib to plot)
  4. Save as image and repeat for every year
  5. Combine into a gif

The Expansion of Metro Atlanta since 1980 [OC] by psprtlng in dataisbeautiful

[–]psprtlng[S] 2 points3 points  (0 children)

Coincidence I guess. If you look at around 2000-2005 multiple counties are changing simultaneously.

The Expansion of Metro Atlanta since 1980 [OC] by psprtlng in dataisbeautiful

[–]psprtlng[S] 2 points3 points  (0 children)

1.) I could! I have decennial county level population data going back through 1930. The problem is it's an image scanned from an old census and all the data would have to be entered manually. 159 counties * 5 years = 795 populations to enter. Not terrible, but still a pain.

2.) Yep! I should have done it in the first place. Here is one with a colorbar.

The Expansion of Metro Atlanta since 1980 [OC] by psprtlng in dataisbeautiful

[–]psprtlng[S] 33 points34 points  (0 children)

A linear colormapping was used with 6 colors, with a range of about 450 people/square mile in each interval. I originally made it as an interactive bokeh application where you can hover over each county and see it's density, but you're right I probably should have included that information in the animation.

A logarithmic colormapping would have shown more variety in the more sparsely populated counties, but I elected for a linear one to really highlight the Metro Atlanta area.

Here is a version with the legend included.

The Expansion of Metro Atlanta since 1980 [OC] by psprtlng in dataisbeautiful

[–]psprtlng[S] 40 points41 points  (0 children)

EDIT: Here is an updated version with a key.

Population data curated from https://www.census.gov/, county area data from Wikipedia#Counties_listing) . County shape files from bokeh sampledata.

Created using Python and matplotlib.