pounce_algorithm/conv_check/trait.rs
1//! `ConvCheck` trait — port of `IpConvCheck.hpp`.
2//!
3//! Upstream `ConvergenceCheck::CheckConvergence` reads the NLP error
4//! and iter count off `IpData()`/`IpCq()`. The default trait method
5//! pushes that read to the caller (the main loop in `ipopt_alg.rs`)
6//! so simple convergence policies stay pure scalar state machines
7//! over `(nlp_err, iter_count)`. The richer
8//! [`ConvCheck::check_convergence_with_state`] entry point exposes
9//! the live `(IpoptData, IpoptCq)` so policies that need iterate
10//! components — notably the restoration-side
11//! `RestoFilterConvergenceCheck::TestOrigProgress` — can read them.
12//! Default impl just delegates to the scalar method, preserving
13//! backwards compatibility for every existing impl.
14
15use crate::ipopt_cq::IpoptCqHandle;
16use crate::ipopt_data::IpoptDataHandle;
17use pounce_common::types::{Index, Number};
18
19#[derive(Debug, Clone, Copy, PartialEq, Eq)]
20pub enum ConvergenceStatus {
21 Continue,
22 Converged,
23 /// Converged to the looser `acceptable_*` tolerance band rather
24 /// than the tight `tol` — upstream `CONVERGED_TO_ACCEPTABLE_POINT`.
25 /// Maps to `SolverReturn::StopAtAcceptablePoint` →
26 /// `ApplicationReturnStatus::SolvedToAcceptableLevel`.
27 ConvergedToAcceptable,
28 MaxIterExceeded,
29 /// `max_cpu_time` budget reached. Maps to
30 /// `SolverReturn::CpuTimeExceeded` → `MaximumCpuTimeExceeded`.
31 CpuTimeExceeded,
32 /// `max_wall_time` budget reached. Maps to
33 /// `SolverReturn::WallTimeExceeded` → `MaximumWallTimeExceeded`.
34 WallTimeExceeded,
35 /// Rapid infeasibility detection fired — the iterate is
36 /// converging to a stationary point of the constraint violation
37 /// with the violation bounded away from zero. Maps to
38 /// `SolverReturn::LocalInfeasibility`.
39 LocallyInfeasible,
40 Failed,
41}
42
43pub trait ConvCheck {
44 fn check_convergence(&mut self, nlp_err: Number, iter_count: Index) -> ConvergenceStatus;
45
46 /// State-aware convergence check. The main loop calls this on
47 /// every iteration so policies that need access to the iterate
48 /// (e.g. `RestoConvCheckAdapter`'s orig-NLP `inf_pr` evaluation
49 /// for the kappa-reduction early-exit) can read `data.curr` and
50 /// the cq layer. Default impl delegates to
51 /// [`Self::check_convergence`], so scalar-only policies don't
52 /// need to override.
53 /// Whether this policy ever refused a termination certificate it judged
54 /// masked by an extreme objective scale (gh #200).
55 ///
56 /// The main loop reads it on the failure exits: a run that was held back
57 /// from stopping must not end up *worse off* than it would have been, so
58 /// when it later stalls the stored acceptable point is restored rather
59 /// than a bare failure surfaced. Policies that never veto keep the
60 /// default `false` and the failure paths behave exactly as before.
61 fn certificate_vetoed(&self) -> bool {
62 false
63 }
64
65 /// Whether this policy ever refused an *acceptable-level* termination it
66 /// judged masked (gh #200). Undone differently from a strict refusal — see
67 /// `OptErrorConvCheck::acceptable_veto_fired`.
68 fn acceptable_certificate_vetoed(&self) -> bool {
69 false
70 }
71
72 fn check_convergence_with_state(
73 &mut self,
74 nlp_err: Number,
75 iter_count: Index,
76 _data: &IpoptDataHandle,
77 _cq: &IpoptCqHandle,
78 ) -> ConvergenceStatus {
79 self.check_convergence(nlp_err, iter_count)
80 }
81
82 /// Whether the current iterate passes the *strict* per-component convergence
83 /// tolerances — the [`Self::check_convergence_with_state`] strict test with
84 /// the masked-certificate veto (gh #200) removed. In other words: would this
85 /// iterate have certified `Success` were it not for the objective-scale
86 /// masking?
87 ///
88 /// gh #327 reads it on the veto's fallback path to distinguish a point the
89 /// veto refused *only because of masking* — a would-be strict certificate,
90 /// e.g. the true optimum a continued run reached but could never certify
91 /// there — from one that never converged at all (an unbounded / diverging
92 /// iterate whose gradient never vanishes). Only the former may displace the
93 /// point the baseline stopped at. Default `false` for policies that expose no
94 /// strict test.
95 fn current_passes_strict(
96 &self,
97 _nlp_err: Number,
98 _data: &IpoptDataHandle,
99 _cq: &IpoptCqHandle,
100 ) -> bool {
101 false
102 }
103
104 /// Whether the supplied `nlp_err` is at or below the acceptable
105 /// tolerance — port of upstream
106 /// `OptimalityErrorConvergenceCheck::CurrentIsAcceptable`. Used by
107 /// the main loop to gate `StoreAcceptablePoint` /
108 /// `RestoreAcceptablePoint`. Default returns `false` so policies
109 /// that don't track an acceptable level (e.g. resto-of-resto inner
110 /// adapters) silently skip the rollback machinery.
111 fn current_is_acceptable(&self, _nlp_err: Number) -> bool {
112 false
113 }
114
115 /// State-aware acceptance check. Mirrors upstream
116 /// `OptimalityErrorConvergenceCheck::CurrentIsAcceptable` which
117 /// reads the per-component residuals and current `f` to gate the
118 /// `acceptable_dual_inf_tol` / `acceptable_constr_viol_tol` /
119 /// `acceptable_compl_inf_tol` / `acceptable_obj_change_tol`
120 /// triplet. Default delegates to the scalar [`Self::current_is_acceptable`].
121 fn current_is_acceptable_with_state(
122 &self,
123 nlp_err: Number,
124 _data: &IpoptDataHandle,
125 _cq: &IpoptCqHandle,
126 ) -> bool {
127 self.current_is_acceptable(nlp_err)
128 }
129
130 /// Record the current objective at the iterate the main loop just
131 /// stashed as the latest "acceptable point" — mirrors upstream
132 /// `OptimalityErrorConvergenceCheck::SetCurrAcceptableF`. The
133 /// recorded value feeds the `acceptable_obj_change_tol` stability
134 /// cross-check on subsequent iterates. Default no-op for policies
135 /// that don't track acceptable points.
136 fn set_curr_acceptable_obj(&mut self, _obj: Number) {}
137
138 /// Outer NLP convergence tolerance, as used by the main loop's
139 /// almost-feasible bypass guard (port of
140 /// `IpBacktrackingLineSearch.cpp:580`). Default `1e-8` matches
141 /// upstream's default `tol`.
142 fn tol_or_default(&self) -> Number {
143 1e-8
144 }
145
146 /// Primal-feasibility tolerance `constr_viol_tol`, in the unscaled max-norm
147 /// space `curr_unscaled_primal_infeasibility_max` reports — the option that
148 /// declares what a *violated* constraint is.
149 ///
150 /// Read by the status-decision sites that have to answer "is this violation
151 /// real" (gh #508). That question is about the constraint violation, so it
152 /// must be asked with the constraint-violation tolerance; asking it with
153 /// `tol` — a tolerance on the **KKT error**, a different quantity in
154 /// different units — makes the answer move when the user retunes
155 /// convergence and stand still when they retune feasibility. Default `1e-4`
156 /// matches upstream's default `constr_viol_tol`; policies that track no such
157 /// tolerance keep it.
158 fn constr_viol_tol_or_default(&self) -> Number {
159 1e-4
160 }
161
162 /// Acceptable-level primal-feasibility band `acceptable_constr_viol_tol`, in
163 /// the unscaled max-norm space `curr_unscaled_primal_infeasibility_max`
164 /// reports. Read by the best-acceptable fallback's feasibility-aware ranking
165 /// (gh #267), which caps it at the upstream default so a user-widened band
166 /// cannot let the fallback spend feasibility to buy objective. Default
167 /// `1e-2` matches upstream's default `acceptable_constr_viol_tol`; policies
168 /// that track no such tolerance keep it.
169 fn acceptable_constr_viol_tol_or_default(&self) -> Number {
170 1e-2
171 }
172
173 /// Live-update a named convergence tolerance mid-solve, for the
174 /// debugger's in-place option hot-swap. Returns `true` if `name`
175 /// matched a tolerance this policy owns (so the caller can report
176 /// whether it took). Default: this policy exposes no live
177 /// tolerances → `false`.
178 fn set_tolerance(&mut self, _name: &str, _value: Number) -> bool {
179 false
180 }
181}