From d4a1467689b3e87041c6b9fa57191c5a2aaf1506 Mon Sep 17 00:00:00 2001
From: Helena Stegherr <helena.stegherr@informatik.uni-augsburg.de>
Date: Mon, 4 Dec 2023 11:02:46 +0100
Subject: [PATCH] Improve according to review comments

---
 src/components/replacement/bh.rs | 32 +++++++++++++++-----------------
 src/components/swarm/bh.rs       | 12 ++++++------
 src/utils.rs                     |  2 +-
 3 files changed, 22 insertions(+), 24 deletions(-)

diff --git a/src/components/replacement/bh.rs b/src/components/replacement/bh.rs
index 2eb4490..a716e1a 100644
--- a/src/components/replacement/bh.rs
+++ b/src/components/replacement/bh.rs
@@ -4,8 +4,8 @@ use rand::Rng;
 use serde::{Deserialize, Serialize};
 
 use crate::{
-    population::BestIndividual, problems::LimitedVectorProblem, utils::squared_euclidean,
-    Component, ExecResult, Individual, SingleObjectiveProblem, State,
+    problems::LimitedVectorProblem, utils::squared_euclidean,
+    Component, ExecResult, SingleObjectiveProblem, State,
 };
 
 #[derive(Clone, Serialize, Deserialize)]
@@ -28,35 +28,33 @@ where
 {
     fn execute(&self, problem: &P, state: &mut State<P>) -> ExecResult<()> {
         let mut populations = state.populations_mut();
-        let offspring = populations.pop();
+        let mut offspring = populations.pop();
 
         let f_bh = state.best_objective_value().unwrap().value();
 
         let fitness_sum = offspring.iter().map(|x| x.objective().value()).sum::<f64>();
         let radius = f_bh / fitness_sum;
 
-        let best_ind = offspring.best_individual().cloned();
-        let best = best_ind.unwrap().solution().clone();
+        let (index, best) = offspring
+            .iter()
+            .enumerate()
+            .min_by_key(|(_u, i)| i.objective())
+            .unwrap();
         let distances = offspring
             .iter()
-            .map(|o| squared_euclidean(o.solution(), &best).sqrt())
+            .map(|o| squared_euclidean(o.solution(), best.solution()).sqrt())
             .collect::<Vec<f64>>();
 
-        let mut new_offspring: Vec<Individual<P>> = vec![];
-        for (u, i) in offspring.iter().enumerate() {
+        for (u, i) in offspring.iter_mut().enumerate() {
             // do not replace best individual
-            if distances[u] < radius && distances[u] != 0.0 {
-                let rand: Vec<f64> = (0..problem.dimension())
-                    .map(|_| state.random_mut().gen_range(problem.domain()[0].clone()))
+            if distances[u] < radius && u != index {
+                let rand: Vec<f64> = problem.domain().iter()
+                    .map(|d| state.random_mut().gen_range(d.clone()))
                     .collect();
-                let j = Individual::new_unevaluated(rand);
-                //println!("{:?}, {:?}", u, &j);
-                new_offspring.push(j);
-            } else {
-                new_offspring.push(i.clone());
+                *i.solution_mut() = rand;
             }
         }
-        populations.push(new_offspring);
+        populations.push(offspring);
         Ok(())
     }
 }
diff --git a/src/components/swarm/bh.rs b/src/components/swarm/bh.rs
index efdb8ec..a4ecd45 100644
--- a/src/components/swarm/bh.rs
+++ b/src/components/swarm/bh.rs
@@ -62,20 +62,20 @@ where
     }
 
     fn execute(&self, _problem: &P, state: &mut State<P>) -> ExecResult<()> {
-        let distr = Uniform::new(0.0, 1.0);
+        let distribution = Uniform::new(0.0, 1.0);
 
         // Get necessary state like global best `xg`
         let best = state.populations().current().best_individual().cloned();
-        let binding = best.unwrap();
-        let xg = binding.solution();
-        let mut binding2 = state.populations_mut();
-        let xs = binding2.current_mut().as_solutions_mut();
+        let best_ind = best.unwrap();
+        let xg = best_ind.solution();
+        let mut population = state.populations_mut();
+        let xs = population.current_mut().as_solutions_mut();
 
         // Perform the update step.
         for x in xs {
             for i in 0..x.len() {
                 // Calculate change in position
-                let pos = distr.sample(&mut *state.random_mut()) * (xg[i] - x[i]);
+                let pos = distribution.sample(&mut *state.random_mut()) * (xg[i] - x[i]);
                 // Add value to particle position
                 x[i] += pos;
             }
diff --git a/src/utils.rs b/src/utils.rs
index ebf09a7..d5a2c7f 100644
--- a/src/utils.rs
+++ b/src/utils.rs
@@ -47,5 +47,5 @@ impl<T> serde::Serialize for SerializablePhantom<T> {
 
 /// Calculates squared Euclidean distance between two vectors.
 pub fn squared_euclidean(a: &[f64], b: &Vec<f64>) -> f64 {
-    a.iter().zip(b).map(|(p, q)| (p - q).powf(2.0)).sum::<f64>()
+    a.iter().zip(b).map(|(p, q)| (p - q).powi(2)).sum::<f64>()
 }