Clean up code and UI, add more fitness rules

Author: JunShern

examples/genetic_music/sketch.js

@@ -7,20 +7,27 @@ var sloop;
 
 var validNotes = [...Array(128).keys()];
 var minValidNote, maxValidNote;
+var songLength = 32; // 4 bars * 8th-note resolution
 
 var maxPopulationSize = 40;
-var numberOfSurvivors = 5;
+var numberOfSurvivors = 10;
 var population = [];
-var songLength = 32; // 4 bars * 8th-note resolution
+var generationCount = 1;
 
 var songIsPlaying = false;
 var clickedEarwormIndex;
 var notePlaybackIndex;
+// Fitness rules
+var desiredKeyClasses = [0,2,4,5,7,9,11];
+var minGoodPitch = 48;
+var maxGoodPitch = 72;
 
 function setup() {
   createCanvas(window.innerWidth, window.innerHeight);
   colorMode(HSB, 255);
   textAlign(CENTER, CENTER);
+  textSize(16);
+  frameRate(10);
 
   sloop = new p5.SoundLoop(soundLoop, 0.3); // Loop plays every 0.3s
   synth = new p5.PolySynth();
@@ -33,39 +40,18 @@ function setup() {
     population.push(song);
   }
 
-  selectionButton = createButton("Selection");
+  selectionButton = createButton("Select 10 fittest");
   selectionButton.mouseClicked(selectFittest);
   selectionButton.position(10, 10);
-  reproductionButton = createButton("Reproduction");
+  reproductionButton = createButton("Reproduce");
   reproductionButton.mouseClicked(reproducePopulation);
   reproductionButton.position(10, 40);
-}
-
-function selectFittest() {
-  // Sort in descending order of fitness
-  population.sort((a, b) => b.fitnessScore - a.fitnessScore);
-  // Keep only the N fittest
-  population = subset(population, 0, numberOfSurvivors);
-  // Re-assign ID numbers
-  for (var i=0; i<population.length; i++) {
-    population[i].id = i;
-  }
-}
-
-function reproducePopulation() {
-  var newPopulation = [];
-  while (newPopulation.length < maxPopulationSize - numberOfSurvivors) {
-    var parentA = random(population);
-    var parentB = random(population);
-    var child = parentA.reproduceWith(parentB);
-    newPopulation.push(child);
-  }
-  // Add new generation to the survivors
-  population = population.concat(newPopulation);
-  // Re-assign ID numbers
-  for (var i=0; i<population.length; i++) {
-    population[i].id = i;
-  }
+  fastForwardButton = createButton("Fast-forward 10 generations");
+  fastForwardButton.mouseClicked(fastForward);
+  fastForwardButton.position(10, 70);
+  resetButton = createButton("Reset population");
+  resetButton.mouseClicked(resetPopulation);
+  resetButton.position(10, 100);
 }
 
 function soundLoop(cycleStartTime) {
@@ -87,10 +73,13 @@ function draw() {
   for (var i=0; i<population.length; i++) {
     population[i].display();
   }
+  fill(255);
   if (songIsPlaying) {
-    fill(255);
     text("Song playing... Click to stop.", width/2, height/2);
+  } else {
+    text("Click on an Earworm to hear it sing!", width/2, height/2);
   }
+  text("Generation: " + generationCount, width/2, height/6);
 }
 
 function mousePressed() {
@@ -112,14 +101,59 @@ function mousePressed() {
   }
 }
 
+function selectFittest() {
+  // Sort in descending order of fitness
+  population.sort((a, b) => b.fitnessScore - a.fitnessScore);
+  // Keep only the N fittest
+  population = subset(population, 0, numberOfSurvivors);
+  // Re-assign ID numbers
+  for (var i=0; i<population.length; i++) {
+    population[i].id = i;
+  }
+}
+
+function reproducePopulation() {
+  var newPopulation = [];
+  while (newPopulation.length < maxPopulationSize - numberOfSurvivors) {
+    var parentA = random(population);
+    var parentB = random(population);
+    var child = parentA.reproduceWith(parentB);
+    newPopulation.push(child);
+  }
+  // Add new generation to the survivors
+  population = population.concat(newPopulation);
+  // Re-assign ID numbers
+  for (var i=0; i<population.length; i++) {
+    population[i].id = i;
+  }
+  generationCount++;
+}
+
+function fastForward() {
+  var fastForwardNum = 10;
+  for (var i=0; i<fastForwardNum; i++) {
+    selectFittest();
+    reproducePopulation();
+  }
+}
+
+function resetPopulation() {
+  generationCount = 1;
+  for (var i=0; i<maxPopulationSize; i++) {
+    var song = new Earworm(i);
+    song.initialize();
+    population[i] = song;
+  }
+}
+
 function Earworm(indexNumber) {
   this.id = indexNumber;
   this.length = songLength;
   this.notes = [];
   // Visual properties
   this.xpos = random(width);
   this.ypos = random(height);
-  this.radius = 30;
+  this.radius = (width + height) / 50;
   this.fitnessScore = 0;
 }
 Earworm.prototype.initialize = function() {
@@ -130,13 +164,16 @@ Earworm.prototype.initialize = function() {
   this.calculateFitness();
 };
 Earworm.prototype.display = function() {
+  this.xpos = constrain(this.xpos + random(-1, 1), 0, width);
+  this.ypos = constrain(this.ypos + random(-1, 1), 0, height);
+
   push();
   strokeWeight(1);
   angleMode(DEGREES); // Change the mode to DEGREES
   var angle = 360 / this.notes.length;
   translate(this.xpos, this.ypos);
   for (var i=0; i<this.notes.length; i++) {
-    var color = map(this.notes[i], minValidNote, maxValidNote, 250, 100);
+    var color = map(this.notes[i], minValidNote, maxValidNote, 280, 120) % 255;
     var length = map(this.notes[i], minValidNote, maxValidNote, this.radius/2, this.radius);
     strokeWeight(1);
     stroke(color, 180, 250);
@@ -160,30 +197,34 @@ Earworm.prototype.display = function() {
 };
 Earworm.prototype.calculateFitness = function() {
   this.fitnessScore = 0;
-  // Self-similarity
   // Key
-  // setA = subset(this.notes, 0, this.notes.length/2);
-  // setB = subset(this.notes, this.notes.length/2, this.notes.length);
-
+  for (var i=0; i<this.notes.length; i++) {
+    var keyClass = this.notes[i] % 12;
+    if (desiredKeyClasses.indexOf(keyClass) >= 0) {
+      this.fitnessScore = this.fitnessScore + 10;
+    }
+  }
+  // Prefer smaller intervals
+  for (var i=0; i<this.notes.length-1; i++) {
+    var currentNote = this.notes[i];
+    var nextNote = this.notes[i+1];
+    var interval = abs(nextNote - currentNote);
+    this.fitnessScore = this.fitnessScore - interval;
+  }
   // Pitch range
-  var minGoodPitch = 40;
-  var maxGoodPitch = 80;
   for (var i=0; i<this.notes.length; i++) {
     if (this.notes[i] > minGoodPitch) {
-      this.fitnessScore = this.fitnessScore + 10;
+      this.fitnessScore = this.fitnessScore + 5;
     }
     if (this.notes[i] < maxGoodPitch) {
-      this.fitnessScore = this.fitnessScore + 10;
-    } 
+      this.fitnessScore = this.fitnessScore + 5;
+    }
   }
-  // Starting and ending on the same note
-  // var startAndEndSame = (this.notes[0] == this.notes[this.notes.length - 1]);
-
-  // Rhythm
 };
 Earworm.prototype.reproduceWith = function(partner) {
-  var partA = subset(this.notes, 0, this.notes.length/2);
-  var partB = subset(partner.notes, partner.notes.length/2, partner.notes.length);
+  var partitionIndex = round(random(this.notes.length));
+  var partA = subset(this.notes, 0, partitionIndex);
+  var partB = subset(partner.notes, partitionIndex, partner.notes.length);
   var child = new Earworm(0);
   child.notes = partA.concat(partB);
   child.mutate(); // Add some random variation
@@ -192,7 +233,7 @@ Earworm.prototype.reproduceWith = function(partner) {
 };
 Earworm.prototype.mutate = function() {
   for (var i=0; i<this.notes.length; i++) {
-    if (random(100) > 90) {
+    if (random(100) > 80) {
       this.notes[i] = random(validNotes);
     }
   }