Get solutions of the Riemann problem associated to the Self-Organized Hydrodynamics (SOH) model, given by $$ \partial_t \rho + \partial_x(\rho\cos\theta) = 0,$$ $$\partial_t \theta + c\partial_x(\sin \theta) - \lambda \frac{\sin\theta}{\rho} \partial_x \rho = 0, $$ where $\rho$ is the density of individuals, $\theta$ the angle of their mean velocity, and $c$ and $\lambda$ are two constants depending on a noise coefficient $d$ (see [Motsch and Navoret] for the computation of $c$ and $\lambda$).
Fill in the noise coefficient and the left and right states, then compute the solution.
Calculations done locally in the navigator via Pyodide. The first loading can take 20 to 45 seconds depending on the connexion.