Struct QpLayer 

pub struct QpLayer { /* private fields */ }

An ADMM-based differentiable QP layer.

Stores problem data and the last forward-pass solution for use in the backward pass.

Implementations

impl QpLayer

pub fn new() -> Self

Create a new QP layer with default configuration.

pub fn with_config(config: QpLayerConfig) -> Self

Create a new QP layer with custom configuration.

pub fn forward( &mut self, q: Vec<Vec<f64>>, c: Vec<f64>, a_eq: Vec<Vec<f64>>, b_eq: Vec<f64>, g_ineq: Vec<Vec<f64>>, h_ineq: Vec<f64>, ) -> OptimizeResult<DiffOptResult>

Solve the QP (forward pass).

Uses ADMM with warm-start. The constraint matrix C = [A_eq; G_ineq] is stacked, and z is projected onto the feasible set:

z_eq = b_eq (equality: exact satisfaction) z_ineq = min(z_ineq_raw, h_ineq) (inequality: clamp to ≤ h)

Arguments

• q – n×n cost matrix (symmetric PSD).
• c – n linear cost vector.
• a_eq – p×n equality constraint matrix.
• b_eq – p equality rhs.
• g_ineq – m×n inequality constraint matrix.
• h_ineq – m inequality rhs.

pub fn backward(&self, dl_dx: &[f64]) -> OptimizeResult<DiffOptGrad>

Backward pass: compute parameter gradients via KKT sensitivity.

Uses the active-set at the solution to identify binding inequality constraints, stacks them with equality constraints, and calls kkt_sensitivity on the resulting system.

Arguments

• dl_dx – upstream gradient dL/dx (length n).

Errors

Returns OptimizeError::ComputationError if no forward pass has been run, or if the KKT system is singular.

pub fn last_solution(&self) -> Option<&[f64]>

Access the cached solution from the last forward pass.

pub fn reset_warm_start(&mut self)

Reset warm-start cache.

Trait Implementations

impl Clone for QpLayer

fn clone(&self) -> QpLayer

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for QpLayer

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

Formats the value using the given formatter.

impl Default for QpLayer

fn default() -> Self

Returns the “default value” for a type.