`scipy.integrate._ivp.radau:solve_collocation_system`

Signature

def solve_collocation_system(fun, t, y, h, Z0, scale, tol, LU_real, LU_complex, solve_lu)

Solve the collocation system.

fun : callable: Right-hand side of the system.
t : float: Current time.
y : ndarray, shape (n,): Current state.
h : float: Step to try.
Z0 : ndarray, shape (3, n): Initial guess for the solution. It determines new values of y at t + h * C as y + Z0, where C is the Radau method constants.
scale : ndarray, shape (n): Problem tolerance scale, i.e. rtol * abs(y) + atol.
tol : float: Tolerance to which solve the system. This value is compared with the normalized by scale error.
LU_real, LU_complex: LU decompositions of the system Jacobians.
solve_lu : callable: Callable which solves a linear system given a LU decomposition. The signature is solve_lu(LU, b).