From 8ab16efe48373f36e999d309bf382cf8338184d7 Mon Sep 17 00:00:00 2001
From: sbosse <sbosse@uni-bremen.de>
Date: Mon, 21 Jul 2025 23:08:04 +0200
Subject: [PATCH] Mon 21 Jul 22:43:21 CEST 2025

---
 js/ml/opt.js | 169 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 169 insertions(+)
 create mode 100644 js/ml/opt.js

diff --git a/js/ml/opt.js b/js/ml/opt.js
new file mode 100644
index 0000000..3d0ca2e
--- /dev/null
+++ b/js/ml/opt.js
@@ -0,0 +1,169 @@
+/**
+ * Created by joonkukang on 2014. 1. 16..
+ */
+var math = require('./utils').math;
+let optimize = module.exports;
+
+optimize.hillclimb = function(options){
+    var domain = options['domain'];
+    var costf = options['costf'];
+
+    var i;
+    var vec = [];
+    for(i=0 ; i<domain.length ; i++)
+        vec.push(math.randInt(domain[i][0],domain[i][1]));
+
+    var current, best;
+
+    while(true) {
+        var neighbors = [];
+        var i,j;
+
+        for(i=0 ; i<domain.length ; i++) {
+            if(vec[i] > domain[i][0]) {
+                var newVec = [];
+                for(j=0 ; j<domain.length ; j++)
+                    newVec.push(vec[j]);
+                newVec[i]-=1;
+                neighbors.push(newVec);
+            } else if (vec[i] < domain[i][1]) {
+                var newVec = [];
+                for(j=0 ; j<domain.length ; j++)
+                    newVec.push(vec[j]);
+                newVec[i]+=1;
+                neighbors.push(newVec);
+            }
+        }
+
+        current = costf(vec);
+        best = current;
+        for(i=0 ; i<neighbors.length ; i++) {
+            var cost = costf(neighbors[i]);
+            if(cost < best) {
+                best = cost;
+                vec = neighbors[i];
+            }
+        }
+        if(best === current)
+            break;
+    }
+    return vec;
+}
+
+optimize.anneal = function(options){
+    var domain = options['domain'];
+    var costf = options['costf'];
+    var temperature = options['temperature'];
+    var cool = options['cool'];
+    var step = options['step'];
+    var callback
+
+    var i;
+    var vec = [];
+    for(i=0 ; i<domain.length ; i++)
+        vec.push(math.randInt(domain[i][0],domain[i][1]));
+
+    while(temperature > 0.1) {
+        var idx = math.randInt(0,domain.length - 1);
+        var dir = math.randInt(-step,step);
+        var newVec = [];
+        for(i=0; i<vec.length ; i++)
+            newVec.push(vec[i]);
+        newVec[idx]+=dir;
+        if(newVec[idx] < domain[idx][0]) newVec[idx] = domain[idx][0];
+        if(newVec[idx] > domain[idx][1]) newVec[idx] = domain[idx][1];
+
+        var ea = costf(vec);
+        var eb = costf(newVec);
+        var p = Math.exp(-1.*(eb-ea)/temperature);
+        if(eb < ea || Math.random() < p)
+            vec = newVec;
+
+        temperature *= cool;
+    }
+
+    return vec;
+}
+
+optimize.genetic = function(options){
+    var domain = options['domain'];
+    var costf = options['costf'];
+    var population = options['population'];
+    var q = options['q'] || 0.3;
+    var elite = options['elite'] || population * 0.04;
+    var epochs = options['epochs'] || 100;
+
+    var i,j;
+    // Initialize population array
+    var pop =[];
+    for(i=0; i<population; i++) {
+        var vec = [];
+        for(j=0; j<domain.length; j++)
+            vec.push(math.randInt(domain[j][0],domain[j][1]));
+        pop.push(vec);
+    }
+    pop.sort(function(a,b){return costf(a) - costf(b);});
+
+    for(i=0 ; i<epochs ; i++) {
+        // elitism
+        var newPop = [];
+        for(j=0;j<elite;j++)
+            newPop.push(pop[j]);
+
+        // compute fitnesses
+        var fitnesses = [];
+        for(j=0; j<pop.length; j++)
+            fitnesses[j] = q * Math.pow(1-q,j);
+        fitnesses = math.normalizeVec(fitnesses);
+
+        // crossover, mutate
+        for(j=0; j<pop.length - elite;j++) {
+            var idx1 = rouletteWheel(fitnesses);
+            var idx2 = rouletteWheel(fitnesses);
+            var crossovered = crossover(pop[idx1],pop[idx2]);
+            var mutated = mutate(crossovered);
+            newPop.push(mutated);
+        }
+
+        // replacement
+        pop = newPop;
+        pop.sort(function(a,b){return costf(a) - costf(b);});
+       //console.log("Current Cost : ",costf(pop[0]));
+    }
+    return pop[0];
+
+    function mutate(vec) {
+        var idx = math.randInt(0,domain.length - 1);
+        var newVec = [];
+        var i;
+        for(i=0; i<domain.length ; i++)
+            newVec.push(vec[i]);
+        newVec[idx] += (Math.random() < 0.5) ? 1 : -1;
+        if(newVec[idx] < domain[idx][0]) newVec[idx] = domain[idx][0];
+        if(newVec[idx] > domain[idx][1]) newVec[idx] = domain[idx][1];
+        return newVec;
+    }
+    function crossover(vec1,vec2) {
+        var idx = math.randInt(0,domain.length - 2);
+        var newVec = [];
+        var i;
+        for(i=0; i<idx ; i++)
+            newVec.push(vec1[i]);
+        for(i=idx; i<domain.length; i++)
+            newVec.push(vec2[i]);
+        return newVec;
+    }
+    function rouletteWheel(vec) {
+        var a = [0.0];
+        var i;
+        for(i=0;i<vec.length;i++) {
+            a.push(a[i] + vec[i]);
+        }
+        var rand = Math.random();
+        for(i=0;i< a.length;i++) {
+            if(rand > a[i] && rand <= a[i+1])
+                return i;
+        }
+        return -1;
+    }
+};