Files
KSP-MGA-Planner/dist/dedicated-workers/libs/evolution.js
Krafpy a05c9e5c9d Major 3D physics and calculation update.
- The 3D physics functions have been moved into a `Physics3D` namespace
- The `TrajectoryCalculator` has been completely recoded and commented
- The `TrajectoryOptimizer` has been recoded accordingly
- Various optimizations focusing on reducing the number of costly
function calls
2021-12-24 02:06:12 +01:00

95 lines
2.9 KiB
JavaScript

"use strict";
class ChunkedEvolver {
constructor(chunkStart, chunkEnd, agentDim, fitness, cr, f) {
this.chunkStart = chunkStart;
this.chunkEnd = chunkEnd;
this.agentDim = agentDim;
this.fitness = fitness;
this.cr = cr;
this.f = f;
const ce = chunkEnd;
const cs = chunkStart;
this.chunkSize = ce - cs + 1;
}
createRandomAgent() {
const agent = Array(this.agentDim);
this.randomizeAgent(agent);
return agent;
}
randomizeAgent(agent) {
for (let i = 0; i < this.agentDim; i++) {
agent[i] = Math.random();
}
}
createRandomPopulationChunk() {
const popChunk = [];
for (let i = 0; i < this.chunkSize; i++) {
popChunk.push(this.createRandomAgent());
}
return popChunk;
}
evaluateChunkFitness(popChunk) {
const fitChunk = Array(popChunk.length);
for (let i = 0; i < popChunk.length; i++) {
fitChunk[i] = this.fitness(popChunk[i]);
}
return fitChunk;
}
evolvePopulationChunk(population, fitnesses) {
const dim = population[0].length;
const nextPopChunk = Array(this.chunkSize);
const nextFitChunk = Array(this.chunkSize);
for (let j = this.chunkStart; j <= this.chunkEnd; j++) {
const x = population[j];
const fx = fitnesses[j];
const [a, b, c] = this._pick3(population, j);
const ri = randint(0, dim - 1);
const y = Array(dim).fill(0);
for (let i = 0; i < dim; i++) {
if (Math.random() < this.cr || i == ri) {
y[i] = a[i] + this.f * (b[i] - c[i]);
}
else {
y[i] = x[i];
}
y[i] = clamp(y[i], 0, 1);
}
const fy = this.fitness(y);
const index = j - this.chunkStart;
if (fy < fx) {
nextPopChunk[index] = y;
nextFitChunk[index] = fy;
}
else {
nextPopChunk[index] = x;
nextFitChunk[index] = fx;
}
}
return {
popChunk: nextPopChunk,
fitChunk: nextFitChunk
};
}
_pick3(population, parentIndex) {
const swap = (arr, i, j) => {
const t = arr[j];
arr[j] = arr[i];
arr[i] = t;
};
swap(population, parentIndex, 0);
const picked = [null, null, null];
const pickedIndices = [0, 0, 0];
for (let i = 0; i <= 2; i++) {
const ri = randint(1 + i, population.length - 1);
picked[i] = population[ri];
pickedIndices[i] = ri;
swap(population, ri, i);
}
for (let i = 2; i >= 0; i--) {
swap(population, pickedIndices[i], i);
}
swap(population, parentIndex, 0);
return picked;
}
}