Compute the value of \(\pi\)¶

The examples iks001_computePi.cpp shows the calculation of \(\pi\) by computing the area and circumference of a unit circle. This example helps to understand the Grid module from Dune and the refinement techniques it brings. The example shows that a global refinement doesn't refine the number of grid entities on the boundary of the circle, which leads to a poor approximation of \(\pi\) while it comparing with the area and circumference of the circle. On the other hand, it also shows how elements on the boundaries can be marked and refined, thereby resulting in an accurate approximation of \(\pi\).