In these ternary plots the racial composition of the city of Chicago and its community areas is decomposed into three groups, Black, White, and non-Black or White. Applying this oversimplified grouping to decennial Census data shows how the axis of polarization in the city has been changing over the last several decades, from one a main axis of either Black or White residents, to a multipolar system having numerous Latin or Asian American communities. The community area data are generously provided by Rob Paral and Associates. The first graph is for the 1980 census, and the second for the 2010 census.
Plotly reference for ternary plots, https://plot.ly/r/reference/#scatterternary.
Chicago Community Area data compilation, Rob Paral and Associates.
Census tract data from decennial censuses 1930 to 2010, U.S. Census Bureau
General reference on Census data, Ari Lamstein and Logan Powell, “A Guide to Working with US Census Data in R”.