Wind rose 3

Here is a script to make a "wind rose 3" in which the area of the central circle is proportional to the frequency of "calm"+"directionless" winds, and the areas of the various colored sectors are proportional to frequency of occurence of that wind. With the area of the central circle having a particular meaning, plotting this windrose requires a bit more than making the radius of the frequency circles proportional to the square root of frequency.

If this has been done correctly, the area of the white "eye" is 9.3% of the total of the colored area + white eye. Consider the winds from 270o. The area of that petal should be 11% of the total, or slightly more than the eye. The winds from 270o with 15 kts < windspeed < 21 kts (red), has a frequency about 0.02 (because .11-.09=.02). Likewise, the winds from 270o with 3 kts < windspeed < 6 kts (blue-green), has a frequency of about 0.02 (because 0.21-.01=.02). Thus the red and blue-green portions should have the same area, which appears to be the case.

The scripts

• Download roseplot3.py