pounce_algorithm/mu/
trait.rs

1//! `MuUpdate` trait — port of `IpMuUpdate.hpp`.
2
3use crate::ipopt_cq::IpoptCqHandle;
4use crate::ipopt_data::IpoptDataHandle;
5use crate::ipopt_nlp::IpoptNlp;
6use crate::kkt::pd_search_dir_calc::PdSearchDirCalc;
7use pounce_common::types::Number;
8use std::cell::RefCell;
9use std::rc::Rc;
10
11pub trait MuUpdate {
12    /// Initialize `data.curr_mu` and `data.curr_tau` before the first
13    /// iteration. Mirrors upstream's `MuUpdate::InitializeImpl`.
14    /// Default is no-op so existing implementors don't have to change.
15    fn initialize(&mut self, _data: &IpoptDataHandle) {}
16
17    /// Compute the next mu after a successful iteration. Mirrors
18    /// upstream's `MuUpdate::UpdateBarrierParameter`. Implementations
19    /// that need the iterate state (adaptive mu, oracles) read it via
20    /// the supplied handles; pure scalar reductions like
21    /// Fiacco-McCormick consult only `data.curr_mu`.
22    ///
23    /// `nlp` and `pd_search_dir` are optional handles needed by the
24    /// adaptive μ oracles that drive an affine-step / centring solve
25    /// (probing, quality-function). When either is `None` the adaptive
26    /// path silently falls back to the LOQO closed form — matching
27    /// upstream's "oracle returned no candidate" branch
28    /// (`IpAdaptiveMuUpdate.cpp:CalculateMuFromOracle:330-340`).
29    fn update_barrier_parameter(
30        &mut self,
31        data: &IpoptDataHandle,
32        cq: &IpoptCqHandle,
33        nlp: Option<&Rc<RefCell<dyn IpoptNlp>>>,
34        pd_search_dir: Option<&mut PdSearchDirCalc>,
35    ) -> Number;
36
37    /// Whether a flagged tiny step with μ unable to decrease should
38    /// terminate the algorithm with `STOP_AT_TINY_STEP`. Upstream
39    /// `IpMonotoneMuUpdate.cpp` throws `TINY_STEP_DETECTED` in exactly
40    /// that case; `IpAdaptiveMuUpdate.cpp` instead routes the tiny-step
41    /// flag through its `force_no_progress` path — it fixes μ and keeps
42    /// iterating, never self-terminating. Default `false` matches the
43    /// adaptive behaviour; `MonotoneMuUpdate` overrides to `true`.
44    fn terminates_on_tiny_step(&self) -> bool {
45        false
46    }
47}
pounce_algorithm/mu/trait.rs

pounce_algorithm/mu/
trait.rs
