pub fn natural_gradient(
gradients: &[f64],
fisher: &Array2<f64>,
regularization: f64,
) -> QuantRS2Result<Vec<f64>>Expand description
Natural gradient for quantum optimization.
Solves the regularized linear system (F + λI) · g_nat = g for the natural
gradient g_nat, where F is the quantum Fisher information matrix, λ the
Tikhonov regularization, and g the Euclidean gradient. The system is
solved by inverting the (symmetric positive-definite after regularization)
matrix via scirs2_linalg.