pounce_algorithm/sqp/
result.rs

1//! `SqpResult` / `SqpStatus` / `SqpError` — return types for
2//! `SqpAlgorithm::optimize`.
3
4use pounce_common::Number;
5use pounce_qp::{QpError, WorkingSet};
6use std::fmt;
7
8#[derive(Debug, Clone, Copy, PartialEq, Eq)]
9pub enum SqpStatus {
10    /// KKT residuals all below their tolerances.
11    Optimal,
12    /// `max_iter` reached without convergence.
13    MaxIter,
14    /// QP subproblem returned an `Infeasible` status (elastic
15    /// mode certified the QP infeasible).
16    InfeasibleSubproblem,
17    /// Line search failed to find an acceptable step (Phase 5b
18    /// commit 5+; not produced by the c3 always-full-step loop).
19    LineSearchFailed,
20    /// The QP subproblem solver neither produced a usable step nor
21    /// certified infeasibility — it hit its own iteration limit or a
22    /// numerical breakdown (e.g. the extreme m/n ≫ 1 degenerate phase-1
23    /// of #282). This is an HONEST non-committal failure: the SQP could
24    /// not compute a search direction, but — unlike `InfeasibleSubproblem`
25    /// — it makes no infeasibility claim it cannot back with a
26    /// certificate. Maps to `Search_Direction_Becomes_Too_Small`.
27    QpStepFailed,
28}
29
30impl fmt::Display for SqpStatus {
31    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
32        match self {
33            SqpStatus::Optimal => write!(f, "optimal"),
34            SqpStatus::MaxIter => write!(f, "max-iter"),
35            SqpStatus::InfeasibleSubproblem => write!(f, "infeasible-subproblem"),
36            SqpStatus::LineSearchFailed => write!(f, "line-search-failed"),
37            SqpStatus::QpStepFailed => write!(f, "qp-step-failed"),
38        }
39    }
40}
41
42#[derive(Debug)]
43pub enum SqpError {
44    /// Hard QP-solver failure (singular, dimension mismatch, etc.).
45    QpFailure(QpError),
46    /// Caller-supplied dimensions disagree.
47    DimensionMismatch(String),
48}
49
50impl fmt::Display for SqpError {
51    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
52        match self {
53            SqpError::QpFailure(e) => write!(f, "QP subproblem failure: {e}"),
54            SqpError::DimensionMismatch(s) => write!(f, "dimension mismatch: {s}"),
55        }
56    }
57}
58
59impl From<QpError> for SqpError {
60    fn from(e: QpError) -> Self {
61        SqpError::QpFailure(e)
62    }
63}
64
65#[derive(Debug, Clone)]
66pub struct SqpResult {
67    pub x: Vec<Number>,
68    pub lambda_g: Vec<Number>,
69    pub lambda_x: Vec<Number>,
70    pub obj: Number,
71    pub status: SqpStatus,
72    pub n_iter: u32,
73    pub n_qp_solves: u32,
74    /// Final stationarity residual (max-norm of `∇f + Jᵀ λ_g + λ_x`).
75    pub final_stationarity: Number,
76    /// Final constraint violation (max-norm of `c(x*)` for
77    /// equalities plus bound-violation slack).
78    pub final_constr_viol: Number,
79    /// Final QP working set, suitable for warm-starting the next
80    /// `optimize_with_warm_start` call (§6 design-note contract).
81    /// `None` only when no QP was solved (e.g. cold-start declared
82    /// the iterate optimal at the very first KKT check).
83    pub working_set: Option<WorkingSet>,
84}
pounce_algorithm/sqp/result.rs

pounce_algorithm/sqp/
result.rs
