It is perfect for a basic view. I think it more useful when each circle visualize the percent of the code base. For example with a pie chart with one value in each circle. The entire circle is mean the 100% of code base (not only that time created), and the value mean how many line created at this times of the current code base. It may be negative, when I commit a lot of bullshit on monday morning and I always change it other commits later, other days or times. It much more visualize the productive and useful times, and show the wrost times for coding.
It is perfect for a basic view. I think it more useful when each circle visualize the percent of the code base. For example with a pie chart with one value in each circle. The entire circle is mean the 100% of code base (not only that time created), and the value mean how many line created at this times of the current code base. It may be negative, when I commit a lot of bullshit on monday morning and I always change it other commits later, other days or times. It much more visualize the productive and useful times, and show the wrost times for coding.