A radial chart of USA airlines on-time performance.

Things to do:

• Add axes (tick marks and labels) for radius
• Choose a different projection for USA map to add Alaska and Hawaii

Things doing:

• Adding axes (tick marks and labels) for angle: using pointRadial

Things have done:

• Used a cleaner way to transform the chart to center
• Learned how to close the line: using d3.curveLinearClosed
• Used a cleaner way to choose the range for radiusScale: innerRadius, outerRadius, angleAxisOffset
• Added a colorLegend
• Made the colorLegend interactive