bugfix:rigid sphere length was not correct
This commit fixes rigid sphere length, previously it was one radius but
it should be two radius.
@@ -16,7 +16,7 @@ class Sphere(RigidBodyBase, _RigidRodSymplecticStepperMixin):
self.radius = base_radius
self.density = density
- self.length = base_radius
+ self.length = 2 * base_radius
# This is for a rigid body cylinder
self.volume = 4.0 / 3.0 * np.pi * base_radius ** 3
self.mass = np.array([self.volume * self.density])
