it seems the formula on that side is incorrect. the newton one the is correct.
look at the list of inertia values here in Wikipedia. and check o the solid cylinder.
https://en.wikipedia.org/wiki/List_of_moments_of_inertiajust make sure the calculation is correct, I overloaded the function that calculate the mass properties of a collision shape for a cylinder.
and the analytical values matches the calculated value form the integration according to the wikipedia expression. but does no matched the one in worphan
give that I am tow independent method that yield the same result, I say is the one in newton that so right.
you can check it out by syncing and setting a break point on line 204 file
...\sdk\dgPhysics\dgCollisionCylinder.cpp
uncomment the analytical expression and the step over to calculate the numerically integrated one.
with in the numerical error coming form the polygonal approximation of the surface done by the numerical integration. the value are equivalent.
The reason this was changed to use the integration and no the analytical formula is that in the engine cylinder can have tow radius. and is more difficult to have a general analytical expression for that kind of shape, if you have a general way of doing the same thong.