croogie

D3 3.5 allows concurrent transitions on the same element provided the transitions have different names. Here, the “position” transition moves the circles up or down, while the “size” transition makes the circles big or small. The names allow the two transitions to work concurrently without interrupting each other.

If named transitions aren’t used, then a later transition can interrupt an earlier transition, preventing it from completing. For example, if the size transition is started shortly after the position transition, it will prevent some of the circles from reaching the end position.

croogie

Unlike choropleth maps, cartograms encode data using area rather than color, resulting in distorted geographic boundaries. In this example, states are rescaled around their centroid, preserving local shape but not topology. Inspired by Zachary Johnson. Non-continguous cartogram design invented by Judy Olsen. U.S. state and county boundaries from the U.S. Census Bureau, simplified using GDAL and MapShaper.