Function update_hessian_with_method 

pub fn update_hessian_with_method(
    hessian: &DMatrix<f64>,
    delta_x: &DVector<f64>,
    delta_g: &DVector<f64>,
    method: HessianUpdateMethod,
) -> DMatrix<f64>

Updates the Hessian matrix using the specified method.

This is the main entry point for Hessian updates, dispatching to the appropriate algorithm based on the selected method.

Arguments

• hessian - Current Hessian matrix (Ha/Ų)
• delta_x - Step vector (x_new - x_old) in Angstrom
• delta_g - Gradient difference (g_new - g_old) in Ha/Å
• method - Update method to use

Returns

Updated Hessian matrix in Ha/Ų.