Struct MetricResidual 

pub struct MetricResidual {
    gradient: Result<DMatrix<Complex>>,
    ks_gradient: [f64; 2],
    dimension: usize,
}

What metric saves for its pullback: the gradient itself, since the value is a real scalar; no singular vectors are kept.

Fields

gradient: Result<DMatrix<Complex>>

The matrix gradient, or why it is undefined: chirality may be zero where its derivative is undefined.

ks_gradient: [f64; 2]

dimension: usize

Implementations

impl MetricResidual

pub fn state_size(dimension: usize) -> Result<usize>

Number of bytes in the fixed derivative state for a square metric input.

impl MetricResidual

pub const fn shape(&self) -> (usize, usize)

The shape of the recorded T-matrix.

pub fn pushforward( &self, matrix: &DMatrix<Complex>, ks: [f64; 2], ) -> Result<f64>

The real metric tangent, from the saved scalar gradient and changes of the T-matrix and embedding wavenumbers, using the real complex inner product.

pub fn pullback(&self, cotangent: f64) -> Result<MetricGradient>

Gradients of the matrix and the embedding wavenumbers from cotangent, the gradient of a real loss with respect to the metric.

The pullback scales the saved gradient on the calling thread, so the Rayon pool does not change it.

Trait Implementations

impl Debug for MetricResidual

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl SavedState for MetricResidual

fn save_state(&self) -> Result<Vec<u8>>

Copy the saved numerical state into its fixed byte layout.

fn from_state(bytes: &[u8]) -> Result<Self>

Restore numerical state from bytes produced by this extension.