Thanks for the reply and thank you very much for the points!!
I changed my function to implement setRadius and I can now set the size of my shape based on a parameter in my json properties. However, I still have 2 challenges..
1) In the formula - (parseFloat(mag) * parseFloat(mag) * parseFloat(mag)) * parseInt(currentZoom) / 30) - 'mag' is from the properties "Magnitude" in your json (.i.e 2.6). This does not appear to be related to specific distance of geography, but rather an arbitrary size based on the magnitude of an earth quake that allows the circles to maintain size in relation to each other, but not a specific distance of geography.
I need to show a circle based on a defined geographic distance. I am passing in a desired raduis of meters (i.e a raduis of 1/2 mile or 926 meters). if I pass in my radius of 926 meters, I end up with a circle that is much larger than a 1 nautical mile diameter when using your formula.
2) while the formula has the current zoom as a parameter, the circle does not maintain a correct of size based on a geographic distance... it occupies more geography or less geography as we zoom in or out. This appears consistent in your demo as well.
Can you please explain the formula and provide an example that will provide a circle radius based on a geographic distance measurement (preferable meters, but I can calculate from any measurement), one that adjusts and maintains correct size based on zoom?