pub fn analyze_stability(
psi: &Array2<f64>,
grid: &Grid2D,
r_eq: f64,
z_eq: f64,
i_plasma_ma: f64,
) -> FusionResult<StabilityResult>Expand description
Full stability analysis: eigenvalue decomposition of the stiffness matrix.
Builds Jacobian K = [[dFr/dR, dFr/dZ], [dFz/dR, dFz/dZ]] via finite differences. Eigenvalues > 0 → stable, < 0 → unstable.