Technically, it's not a pie chart, it's a rose diagram or polar area diagram. More info here: http://vis.stanford.edu/protovis/ex/crimea-rose.html http://vis.s

Technically, it's not a pie chart, it's a rose diagram or polar area diagram. More info here: http://vis.stanford.edu/protovis/ex/crimea-rose.html http://vis.stanford.edu/protovis/ex/crimea-rose.html