# rigidbody¶

probnum.diffeq.rigidbody(timespan, initrv)[source]

Initial value problem (IVP) for rigid body dynamics without external forces

The rigid body dynamics without external forces is defined through

$\begin{split}f(t, y) = \begin{pmatrix} y_2 y_3 \\ -y_1 y_3 \\ -0.51 \cdot y_1 y_2 \end{pmatrix}\end{split}$

The ODE system has no parameters. This implementation includes the Jacobian $$J_f$$ of $$f$$.

Parameters
• timespan ((float, float)) – Time span of IVP.

• initrv (RandomVariable,) – (shape=(3, )) – Vector-valued RandomVariable that describes the belief over the initial value. Usually it is a Constant (noise-free) or Normal (noisy) Random Variable with $$3$$-dimensional mean vector and $$3 \times 3$$-dimensional covariance matrix. To replicate “classical” initial values use the Constant distribution.

Returns

IVP object describing the rigid body dynamics IVP with the prescribed configuration.

Return type

IVP