# HG changeset patch
# User Tuomo Valkonen <tuomov@iki.fi>
# Date 1669997320 -7200
# Node ID c32171f7cce5a86c133e8af08b62aae2561176e9
# Parent  bcb508479948e1bc835955aef669b9310db0456a
Remove ergodic tolerance; it's not useful.

diff -r bcb508479948 -r c32171f7cce5 src/fb.rs
--- a/src/fb.rs	Thu Dec 01 23:37:14 2022 +0200
+++ b/src/fb.rs	Fri Dec 02 18:08:40 2022 +0200
@@ -80,7 +80,6 @@
 */
 
 use numeric_literals::replace_float_literals;
-use std::cmp::Ordering::*;
 use serde::{Serialize, Deserialize};
 use colored::Colorize;
 use nalgebra::DVector;
@@ -156,16 +155,6 @@
     InertiaFISTA,
 }
 
-/// Ergodic tolerance application style
-#[derive(Clone, Copy, Eq, PartialEq, Serialize, Deserialize, Debug)]
-#[allow(dead_code)]
-pub enum ErgodicTolerance<F> {
-    /// Non-ergodic iteration-wise tolerance
-    NonErgodic,
-    /// Bound after `n`th iteration to `factor` times value on that iteration.
-    AfterNth{ n : usize, factor : F },
-}
-
 /// Settings for [`pointsource_fb`].
 #[derive(Clone, Copy, Eq, PartialEq, Serialize, Deserialize, Debug)]
 #[serde(default)]
@@ -190,8 +179,6 @@
     /// Stop looking for predual maximum (where to isert a new point) below
     /// `tolerance` multiplied by this factor.
     pub insertion_cutoff_factor : F,
-    /// Apply tolerance ergodically
-    pub ergodic_tolerance : ErgodicTolerance<F>,
     /// Settings for branch and bound refinement when looking for predual maxima
     pub refinement : RefinementSettings<F>,
     /// Maximum insertions within each outer iteration
@@ -230,7 +217,6 @@
             insertion_style : InsertionStyle::Reuse,
             tolerance : Default::default(),
             insertion_cutoff_factor : 1.0,
-            ergodic_tolerance : ErgodicTolerance::NonErgodic,
             refinement : Default::default(),
             max_insertions : 100,
             //bootstrap_insertions : None,
@@ -554,10 +540,6 @@
     // Initialise iterates
     let mut μ = DiscreteMeasure::new();
 
-    let mut after_nth_bound = F::INFINITY;
-    // FIXME: Don't allocate if not needed.
-    let mut after_nth_accum = opA.zero_observable();
-
     let mut inner_iters = 0;
     let mut this_iters = 0;
     let mut pruned = 0;
@@ -628,15 +610,10 @@
         };
 
         // Calculate smooth part of surrogate model.
-        residual *= -τ;
-        if let ErgodicTolerance::AfterNth{ .. } = config.ergodic_tolerance {
-            // Negative residual times τ expected here, as set above.
-            // TODO: is this the correct location?
-            after_nth_accum += &residual;
-        }
         // Using `std::mem::replace` here is not ideal, and expects that `empty_observable`
         // has no significant overhead. For some reosn Rust doesn't allow us simply moving
         // the residual and replacing it below before the end of this closure.
+        residual *= -τ;
         let r = std::mem::replace(&mut residual, opA.empty_observable());
         let minus_τv = preadjA.apply(r);     // minus_τv = -τA^*(Aμ^k-b)
         // TODO: should avoid a second copy of μ here; μ_base already stores a copy.
@@ -688,40 +665,9 @@
                 count > 0
             };
 
-            // First do a rough check whether we are within bounds and can stop.
-            let in_bounds = match config.ergodic_tolerance {
-                ErgodicTolerance::NonErgodic => {
-                    target_bounds.superset(&d.bounds())
-                },
-                ErgodicTolerance::AfterNth{ n, factor } => {
-                    // Bound -τ∑_{k=0}^{N-1}[A_*(Aμ^k-b)+α] from above.
-                    match state.iteration().cmp(&n) {
-                        Less => true,
-                        Equal => {
-                            let iter = F::cast_from(state.iteration());
-                            let mut tmp = preadjA.apply(&after_nth_accum);
-                            let (_, v0) = tmp.maximise(refinement_tolerance,
-                                                    config.refinement.max_steps);
-                            let v = v0 - iter * τ * α;
-                            after_nth_bound = factor * v;
-                            println!("{}", format!("Set ergodic tolerance to {}", after_nth_bound));
-                            true
-                        },
-                        Greater => {
-                            // TODO: can divide after_nth_accum by N, so use basic tolerance on that.
-                            let iter = F::cast_from(state.iteration());
-                            let mut tmp = preadjA.apply(&after_nth_accum);
-                            tmp.has_upper_bound(after_nth_bound + iter * τ * α,
-                                                refinement_tolerance,
-                                                config.refinement.max_steps)
-                        }
-                    }
-                }
-            };
-
             // If preliminary check indicates that we are in bonds, and if it otherwise matches
             // the insertion strategy, skip insertion.
-            if may_break && in_bounds {
+            if may_break && target_bounds.superset(&d.bounds()) {
                 break 'insertion (true, d)
             }