this iteration ensures that a formatted population value appears on the tooltip
it also sets the margins to 0 and
updates the width to 960 pixels and the height to 500pixels
so that the map fits nicely on bl.ocks.org
🙏 to @Jeremy_CF_Lin for creating this nice world population map bl.ock that is the basis for these iterations
do check out the other examples in this world map series:
world map 00 original example
world map 01 fix tooltip value
world map 02 d3 v4
world map 03 es2015 + update code style
world map 04 manual breaks + threshold scale
world map 05 linear breaks + quantize scale
world map 06 linear breaks + quantiles scale
world map 07 Jenks natural breaks
world map 08 ckmeans cluster max breaks
world map 09 ckmeans cluster min breaks