Function pendulum::simulator::integrate::implicit::solve_linear_system

fn solve_linear_system(
    nitems: usize,
    a: &mut Vec<f64>,
    x: &mut Vec<f64>,
    b: &mut Vec<f64>
) -> f64

Solves a linear system: A x = b.

I assume x contains the previous solution of the system. The result A^{-1} b is first stored in b, which are compared with x to measure how close to the convergence the system is.