Low performance when inserting large amount of dynamic DOM elements - javascript

I need to create a flow script which inserts 1000s elements per second in different columns, when amount reaches 30 elements per column I'm deleting them.
I noticed I can use CSS to insert my data, by the sheer number of DOM elements slows down when I have let's say 100 columns and 50 rows in each; and the whole process becomes choppy.
I'm creating the elements and storing in array to also improve the performance.
How to perform this task with better performance in pure JavaScript?
https://jsfiddle.net/r7qpmd4o/4/
<script>
var elems = [],
buffer = 1000,
temp_row,
temp_col,
temp_var;
// run
create();
clock();
function clock() {
setInterval(function() {
for(var i = 0; i < 10; i++) {
temp_col = document.getElementById('col' + i);
temp_row = pop();
if(temp_col.firstChild) {
temp_col.insertBefore(temp_row, temp_col.firstChild);
}
else {
temp_col.appendChild(temp_row);
}
if(temp_col.childNodes.length > 30) {
temp_col.removeChild(temp_col.childNodes[30]);
}
}
}, 1);
}
function pop() {
if(elems.length < 1) {
create();
}
temp_var = elems[elems.length -1];
elems.pop();
return temp_var;
}
function create() {
for(var i = 0; i < buffer; i++) {
temp_row = document.createElement('div');
temp_row.className = 'a';
elems.push(temp_row);
}
console.log('Elems created: ' + buffer);
}
</script>

<script>
var elems = [],
buffer = 1000,
temp_row,
temp_col,
temp_var;
// run
create();
clock();
var nodeCOunter = 0; //counts what node until 30 hits
function clock() {
setInterval(function() {
for(var i = 0; i < 10; i++) {
temp_col = document.getElementById('col' + i);
temp_row = pop();
if(temp_col.firstChild) {
temp_col.insertBefore(temp_row, temp_col.firstChild);
}
else {
temp_col.appendChild(temp_row);
}
if(nodeCounter == 30){
temp_col.removeChild(temp_col.childNodes[30]);
nodeCounter = 0; //reset
}
else
{
nodeCounter += 1;
}
}, 1);
}
function pop() {
if(elems.length < 1) {
create();
}
temp_var = elems[elems.length -1];
elems.pop();
return temp_var;
}
function create() {
for(var i = 0; i < buffer; i++) {
temp_row = document.createElement('div');
temp_row.className = 'a';
elems.push(temp_row);
}
console.log('Elems created: ' + buffer);
}

You might try switching out setInterval for requestAnimationFrame and then place the content of your create function at the top of your clock function. The function call is a pretty expensive one.
Live Example: http://codepen.io/larryjoelane/pen/GodmXE
JavaScript:
var elems = [],
buffer = 1000,
temp_row,
temp_col,
temp_var;
// run
//create();
clock();
function clock() {
//formally part of the create
//function
for(var i = 0; i < buffer; i++) {
temp_row = document.createElement('div');
temp_row.className = 'a';
elems.push(temp_row);
}
console.log('Elems created: ' + buffer);
//end create function
window.requestAnimationFrame(function() {
for(var i = 0; i < 10; i++) {
temp_col = document.getElementById('col' + i);
temp_row = pop();
if(temp_col.firstChild) {
temp_col.insertBefore(temp_row, temp_col.firstChild);
}
else {
temp_col.appendChild(temp_row);
}
if(temp_col.childNodes.length > 30) {
temp_col.removeChild(temp_col.childNodes[30]);
}
}
window.requestAnimationFrame(clock);
});
}
function pop() {
if(elems.length < 1) {
create();
}
temp_var = elems[elems.length -1];
elems.pop();
return temp_var;
}
function create() {
}

Related

I'm trying to make this code in vanilla javascript work in reactjs, but it's falling into the infinite loop

This is the code i got from codepen, it generates special characters and changes to the phrase i put, I'm wanting to compile this vanilla javascript code to react, because you can't use the DOM
there.
My real doubt is where do I put the useState so that it stops looping and shows character by character, this passing for example the state 'title' in a .
vanilla javascript code:
function setCharAt(str,index,chr) {
if(index > str.length-1) return str;
return str.substr(0,index) + chr + str.substr(index+1);
}
var characters = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890-=+<>,./?[{()}]!##$%^&*~`\|'.split('');
var progress404 = 0;
var total404 = $('.text__error').data('text').length;
var progressLink = 0;
var totalLink = $('.text__link a').data('text').length;
var scrambleInterval = setInterval(function() {
var string404 = $('.text__error').data('text');
var stringLink = $('.text__link a').data('text');
for(var i = 0; i < total404; i++) {
if(i >= progress404) {
string404 = setCharAt(string404, i, characters[Math.round(Math.random() * (characters.length - 1))]);
}
}
for(var i = 0; i < totalLink; i++) {
if(i >= progressLink) {
stringLink = setCharAt(stringLink, i, characters[Math.round(Math.random() * (characters.length - 1))]);
}
}
$('.text__error').text(string404);
$('.text__link a').text(stringLink);
}, 1000 / 60);
setTimeout(function() {
var revealInterval = setInterval(function() {
if(progress404 < total404) {
progress404++;
}else if(progressLink < totalLink) {
progressLink++;
}else{
clearInterval(revealInterval);
clearInterval(scrambleInterval);
}
}, 50);
}, 1000);
This is the code I developed to try to work:
const [ title, setTitle ] = useState('404 page not found')
const [ link, setLink ] = useState('click here to go home')
function setCharAt(str: string,index: number,chr: any) {
if(index > str.length-1) return str;
return str.substr(0,index) + chr + str.substr(index+1);
}
var characters = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890-=+<>,./?[{()}]!##$%^&*~`\|'.split('');
var progress404 = 0;
var total404 = title.length
var progressLink = 0;
var totalLink = link.length
var scrambleInterval = setInterval(function() {
for(var i = 0; i < total404; i++) {
if(i >= progress404) {
setTitle( setCharAt(title, i, characters[Math.round(Math.random() * (characters.length - 1))]));
}
}
for(var i = 0; i < totalLink; i++) {
if(i >= progressLink) {
setLink( setCharAt(link, i, characters[Math.round(Math.random() * (characters.length - 1))]));
}
}
}, 1000 / 60);
setTimeout(function() {
var revealInterval = setInterval(function() {
if(progress404 < total404) {
progress404++;
}else if(progressLink < totalLink) {
progressLink++;
}else{
clearInterval(revealInterval);
clearInterval(scrambleInterval);
}
}, 50);
}, 1000);

update priority of queue in javascript

in hasValue class, why return is not working? when i try with console.log and alert, it worked.
want to implement function like priorityQueue.changePriority("Sheru", 1); changePriority class is not working.
commented code is code i tried to implement the changes i.e. i want to change the priority of existing item present in queue. Could anyone please help?
class QElement {
constructor(element, priority) {
this.element = element;
this.priority = priority;
}
}
class PriorityQueue {
constructor() {
this.items = [];
}
isEmpty() {
return this.items.length == 0;
}
add(element, priority) {
var qElement = new QElement(element, priority);
var contain = false;
for (var i = 0; i < this.items.length; i++) {
if (this.items[i].priority > qElement.priority) {
this.items.splice(i, 0, qElement);
contain = true;
break;
}
}
if (!contain) {
this.items.push(qElement);
}
}
peek() {
if (this.isEmpty())
return "No elements in Queue";
return this.items[0];
}
poll() {
if (this.isEmpty())
return "Underflow";
return this.items.shift();
}
/*changePriority(firstTerm, secondTerm)
{
let xxx = new QElement(firstTerm, secondTerm);
for (let i = 0; i < this.items.length; i++){
if (this.items[i].element === firstTerm){
this.items[i].priority = secondTerm;
this.items.splice(i, 0, xxx);
}
}
this.items.push(xxx);
}*/
hasValue(args) {
let status = false;
for (let i = 0; i < this.items.length; i++) {
if (this.items[i].element === args) {
status = true;
}
}
console.log(status);
}
size() {
if (this.isEmpty())
return "Underflow";
return this.items.length;
}
printPQueue() {
var str = "";
for (var i = 0; i < this.items.length; i++)
str += this.items[i].element + " ";
return str;
}
}
var priorityQueue = new PriorityQueue();
console.log(priorityQueue.isEmpty());
console.log(priorityQueue.peek());
priorityQueue.add("Sumit", 2);
priorityQueue.add("Gourav", 1);
priorityQueue.add("Piyush", 1);
priorityQueue.add("Sunny", 2);
priorityQueue.add("Sheru", 3);
console.log(priorityQueue.printPQueue());
console.log(priorityQueue.peek().element);
console.log(priorityQueue.poll().element);
priorityQueue.add("Sunil", 2);
console.log(priorityQueue.size());
priorityQueue.hasValue('Sumit');
console.log(priorityQueue.printPQueue());
priorityQueue.changePriority("Sheru", 1);
console.log(priorityQueue.printPQueue());
You missing return keyword. This just works:
hasValue(args) {
for (let i = 0; i < this.items.length; i++) {
if (this.items[i].element === args) {
return true;
}
}
return false;
}
I did not understand the idea how your changePriority function should work. Just find the element and move it up or down based on priority change:
swap(a, b) {
let tmp = this.items[a];
this.items[a] = this.items[b];
this.items[b] = tmp;
}
changePriority(firstTerm, secondTerm) {
let i = 0;
while (i < this.items.length) {
if (this.items[i].element === firstTerm) {
if (secondTerm < this.items[i].priority) {
// move up
this.items[i].priority = secondTerm;
while (i > 0 && this.items[i - 1].priority > secondTerm) {
this.swap(i - 1, i);
i--;
}
} else if (secondTerm > this.items[i].priority) {
// move down
this.items[i].priority = secondTerm;
while (i < this.items.length - 1 && this.items[i + 1].priority < secondTerm) {
this.swap(i + 1, i);
i++;
}
}
break;
}
i++;
}
}

How to pause the entire code for 1 second in javascript

I am trying to code an evolutionary neural network for the game snake. I already coded the neural network part and now I'd like to output the game of the best individual of every generation. For that I'm using the drawing library p5.js (https://p5js.org/).
In my code I am running a loop in where a new generation based on the last generation is created. Each individual of the generation will have to play the game and that is how they are rated. Now I want the best individual to be outputted after I let every individual play once.
Between each outputted turn of the game of the best individual I want the code to wait 500 milliseconds. How do I achieve that?
Here is the code I've already tried but here it only outputed the board after the last turn of each generation:
async function start() {
for (let i = 0; i < 50; i++) {
population.createNewGeneration();
let bestGameTurns = population.bestIndividual.game.turns; //Array of boards
for (let turn = 0; turn < bestGameTurns.length; turn++) {
let board = bestGameTurns[turn];
drawBoard(board);
let p = new Promise(resolve => setTimeout(resolve, 500));
await p;
function drawBoard(board) {
//Draw the board using p5.js rect()'s
}
}
}
}
Another version but the waiting didn't work here:
let i = 0;
setInterval(async () => {
population.createNewGeneration();
console.log(i, population.avgFitness);
let bestGameTurns = population.bestIndividual.game.turns; //Array of boards
for (let turn = 0; turn < bestGameTurns.length; turn++) {
let board = bestGameTurns[turn];
drawBoard(board);
let p = new Promise(resolve => setTimeout(resolve, 500));
await p;
function drawBoard(board) {
//Draw the board using p5.js rect()'s
}
}
i++;
}, 1);
The code you provided should do what you asked for, I could only clean up some parts for you. Explain a bit better what is the problem you are facing.
// The function should be defined only once.
function drawBoard(board) { }
async function start() {
for (let i = 0; i < 50; i++) {
population.createNewGeneration();
const bestGameTurns = population.bestIndividual.game.turns; //Array of boards
for (let turn = 0; turn < bestGameTurns.length; turn++) {
// Don't wait on first iteration
await new Promise(resolve => setTimeout(resolve, 500 * (turn ? 0 : 1 )));
drawBoard(bestGameTurns[turn]);
}
}
}
Original idea (discarded)
You can create a short function like that:
function pause(ms) {
return new Promise((resolve) => setTimeout(resolve, ms));
}
Then in any async function you can call it like that:
async function () {}
// something happening
await pause(500);
// continue
}
The other idea
Now, the code in your question is not complete so this is kind of blind coding but.
So, first of all setInterval will be running the whole function every 1 millisecond (actually 4 ms, as this is the minimum in JS). Which means it will run those loops. I decided to focus on the part that was marked by you.
Instead of loop and trying to pause it, I ask that maybe rewriting the loop into function called each half second until condition is met would do?
Also, I move drawBoard outside
setInterval(async () => {
// ^^^^^^^^ <-- this should probably go
population.createNewGeneration();
console.log(i, population.avgFitness);
let bestGameTurns = population.bestIndividual.game.turns; //Array of boards
function tick(turn = 0) {
let board = bestGameTurns[turn];
function drawBoard(board) {
//Draw the board using p5.js rect()'s
}
drawBoard(board);
// here is "setTimeouted" loop
if (turn < bestGameTurns.length) {
setTimeout(tick, 500, turn + 1);
}
}
tick();
}, 1);
Thanks to everyone, your suggestions brought me to an idea. I found out that the problem was lying somewhere else. Because javascript only runs on the one thread (I think thats how its called), after we run over one generation, we have to stop that function to let another draw function, which runs every frame, draw the board. After it is drawn, the main function can continue. This is how it looks:
let isDrawn = false;
let currentBoard;
async function setup() {
for (let i = 0; i < 50; i++) {
population.createNewGeneration();
const bestGameTurns = population.bestIndividual.game.turns;
for (let turn = 0; turn < bestGameTurns.length; turn++) {
await step(bestGameTurns[turn], turn);
}
}
}
function step(board, turn) {
currentBoard = board;
isDrawn = false;
return new Promise(resolve => setTimeout(() => {
if (isDrawn) resolve();
}, 500));
}
setTimeout(() => {
if (currentBoard) {
drawBoard(currentBoard);
isDrawn = true;
currentBoard = undefined;
}
}, 1);
const nrOfCols = 10;
const nrOfRows = 10;
const fieldWidth = 20;
const nodeNrs = [24, 8, 8, 4];
const populationSize = 200;
const mutationRate = 0.01;
let population;
let game;
let isDrawn = false;
let currentBoard;
async function setup() {
createCanvas(500, 500);
population = new PopulationManager(populationSize);
for (let i = 0; i < 50; i++) {
population.createNewGeneration();
const bestGameTurns = population.bestIndividual.game.turns;
for (let turn = 0; turn < bestGameTurns.length; turn++) {
await step(bestGameTurns[turn]);
}
}
}
function step(board) {
currentBoard = board;
isDrawn = false;
return new Promise(resolve => setTimeout(() => {
if (isDrawn) resolve();
}, 500));
}
function draw() {
if (currentBoard) {
drawBoard(currentBoard);
isDrawn = true;
currentBoard = undefined;
}
}
function drawBoard(board) {
board.forEach((col, colNr) => {
col.forEach((field, rowNr) => {
fill(field.isSnake ? "green" : field.isFruit ? "red" : "black");
stroke(255);
rect(colNr*fieldWidth, rowNr*fieldWidth, fieldWidth, fieldWidth);
});
});
}
function play(game) {
setInterval(() => {
if (!game.lost) {
game.nextTurn();
drawBoard(game.board);
} else {
clearInterval(1);
}
}, 500);
}
class PopulationManager {
constructor(populationSize) {
this.population = createPopulation();
function createPopulation() {
let population = [];
for (let i = 0; i < populationSize; i++) {
let chromosomes = createRandomChromosomes();
let i = new Individual(chromosomes);
population.push(i);
}
return population;
function createRandomChromosomes() {
let arr = [];
let nrOfChromosomes = calcNrOfChromosomes();
for (let i = 0; i < nrOfChromosomes; i++)
arr.push(Math.random()*2-1);
return arr;
function calcNrOfChromosomes() {
let nr = 0;
for (let i = 0; i < nodeNrs.length - 1; i++)
nr += (nodeNrs[i] + 1)*nodeNrs[i + 1];
return nr;
}
}
};
}
createNewGeneration() {
let that = this;
getFitnessOfPop();
this.calcAvgFitness();
this.findBestIndividual();
let parents = selection();
breed(parents);
function getFitnessOfPop() {
that.population.forEach(iv => {
iv.fitness = iv.playGame();
});
that.population.sort((a, b) => a.fitness - b.fitness);
}
function selection() {
let totalFitness = that.population.map(iv => iv.fitness/* + 1 */).reduce((a,b) => a + b);
let allParents = [];
for (let i = 0; i < that.population.length/2; i++) {
allParents.push(selectRandomParents());
}
return allParents;
function selectRandomParents() {
let p1, p2;
do {
p1 = selectRandomParent();
p2 = selectRandomParent();
} while (p1 == p2);
return [p1, p2];
function selectRandomParent() {
let rdm = Math.random()*totalFitness;
return that.population.find((iv, i) => {
let sum = that.population.filter((iv2, i2) => i2 <= i).map(iv => iv.fitness /* + 1 */).reduce((a,b) => a + b);
return rdm <= sum;
});
}
}
}
function breed(allParents) {
that.population = [];
allParents.forEach(ps => {
let childChromosomes = crossOver(ps[0].chromosome, ps[1].chromosome);
childChromosomes = [mutate(childChromosomes[0]), mutate(childChromosomes[1])];
let child1 = new Individual(childChromosomes[0]);
let child2 = new Individual(childChromosomes[1]);
that.population.push(child1);
that.population.push(child2);
});
function crossOver(parent1Chromosome, parent2Chromosome) {
let crossingPoint = Math.round(Math.random()*parent1Chromosome.length);
let divided1 = divideChromosome(parent1Chromosome);
let divided2 = divideChromosome(parent2Chromosome);
let child1Chromosome = divided1[0].concat(divided2[1]);
let child2Chromosome = divided2[0].concat(divided1[1]);
return [child1Chromosome, child2Chromosome];
function divideChromosome(chromosome) {
let part1 = chromosome.filter((g, i) => i <= crossingPoint);
let part2 = chromosome.filter((g, i) => i > crossingPoint);
return [part1, part2];
}
}
function mutate(chromosome) {
chromosome = chromosome.map(g => {
if (Math.random() < mutationRate)
return Math.random()*2-1;
return g;
});
return chromosome;
}
}
}
calcAvgFitness() {
this.avgFitness = this.population.map(iv => iv.fitness).reduce((a, b) => a + b) / this.population.length;
}
findBestIndividual() {
let bestFitness = -1, bestIndividual;
this.population.forEach(i => {
if (i.fitness > bestFitness) {
bestFitness = i.fitness;
bestIndividual = i;
}
});
this.bestIndividual = bestIndividual;
}
}
class Individual {
constructor(chromosome) {
this.chromosome = chromosome;
this.fitness = 0;
this.game = createGame();
function createGame() {
let weights = convertChromosomeToWeights();
let game = new Game(weights);
return game;
function convertChromosomeToWeights() {
let weights = [];
for (let i = 0; i < nodeNrs.length - 1; i++) {
let lArr = [];
for (let j = 0; j < nodeNrs[i] + 1; j++) {
let nArr = [];
lArr.push(nArr);
}
weights.push(lArr);
}
chromosome.forEach((gene, geneIdx) => {
let lIdx = -1, minIdx, maxIdx = 0;
for (let i = 0; i < nodeNrs.length - 1; i++) {
let nr = 0;
for (let j = 0; j <= i; j++)
nr += (nodeNrs[j] + 1)*nodeNrs[j + 1];
if (geneIdx < nr) {
lIdx = i;
break;
}
maxIdx = nr;
minIdx = maxIdx;
}
minIdx = maxIdx;
let nIdx = -1;
for (let i = 0; i < nodeNrs[lIdx] + 1; i++) {
let nr = minIdx + nodeNrs[lIdx + 1];;
if (geneIdx < nr) {
nIdx = i;
break;
}
maxIdx = nr;
minIdx = maxIdx;
}
minIdx = maxIdx;
let wIdx = -1;
for (let i = 0; i < nodeNrs[lIdx + 1]; i++) {
let nr = minIdx + 1;
if (geneIdx < nr) {
wIdx = i;
break;
}
maxIdx = nr;
minIdx = maxIdx;
}
weights[lIdx][nIdx][wIdx] = gene;
});
return weights;
}
}
}
playGame() {
while (!this.game.lost) {
this.game.nextTurn();
}
return this.game.score;
}
}
class Game {
constructor(weights) {
let that = this;
this.chromosome = flattenArray(weights);
this.nn = new NeuralNetwork(weights);
this.turnNr = 0;
this.score = 0;
this.lost = false;
this.board = createBoard();
this.snake = new Snake();
setupSnake();
this.createFruit();
this.turns = [JSON.parse(JSON.stringify(this.board))];
function createBoard() {
let board = [];
for (let colNr = 0; colNr < nrOfCols; colNr++) {
board[colNr] = [];
for (let rowNr = 0; rowNr < nrOfRows; rowNr++) {
let field = new Field(colNr, rowNr);
board[colNr][rowNr] = field;
}
}
return board;
}
function setupSnake() {
for (let i = 0; i < 4; i++)
that.addToTail([floor(nrOfCols/2) - i, floor(nrOfRows/2)]);
that.length = that.snake.body.length;
}
function flattenArray(arr) {
let flattened = [];
flatten(arr);
return flattened;
function flatten(arr) {
arr.forEach(e => {
if (Array.isArray(e))
flatten(e);
else
flattened.push(e);
});
}
}
}
addToTail(pos) {
this.snake.body.push(pos);
this.board[pos[0]][pos[1]].setSnake(true);
}
nextTurn() {
let that = this;
let direction = findDirection();
this.moveSnake(direction);
this.turns.push(JSON.parse(JSON.stringify(this.board)));
this.turnNr++;
checkEat();
function findDirection() {
let inputValues = [];
for (let i = 0; i < 8; i++) {
let distances = that.snake.look(i, that.board);
inputValues.push(distances.distToFruit);
inputValues.push(distances.distToWall);
inputValues.push(distances.distToBody);
}
let output = that.nn.getOutput(inputValues);
let probability = -1;
let direction = -1;
output.forEach((v, vIdx) => {
if (v > probability) {
probability = v;
direction = vIdx;
}
});
return direction;
}
function checkEat() {
let head = that.snake.body[0];
let headField = that.board[head[0]][head[1]];
if (headField.isFruit) {
that.snake.eat();
that.score++;
headField.setFruit(false);
that.createFruit();
}
}
}
createFruit() {
let field;
do {
let colNr = floor(random()*nrOfCols);
let rowNr = floor(random()*nrOfRows);
field = this.board[colNr][rowNr];
} while(field.isSnake);
field.setFruit(true);
}
moveSnake(newDirection) {
let that = this;
let oldBody = JSON.parse(JSON.stringify(that.snake.body));
moveTail();
makeSnakeLonger();
moveHead();
function moveTail() {
for (let i = oldBody.length - 1; i > 0; i--)
that.snake.body[i] = oldBody[i - 1];
}
function moveHead() {
let newHeadPosition = findNewHeadPos();
if (
newHeadPosition[0] >= nrOfCols || newHeadPosition[0] < 0 ||
newHeadPosition[1] >= nrOfRows || newHeadPosition[1] < 0
) {
that.lose();
return;
}
let newHeadField = that.board[newHeadPosition[0]][newHeadPosition[1]];
if (newHeadField.isSnake) {
that.lose();
return;
}
addNewHeadPos(newHeadPosition);
}
function findNewHeadPos() {
if (newDirection == 0) { //up
return [oldBody[0][0], oldBody[0][1] - 1];
} else if (newDirection == 1) { //right
return [oldBody[0][0] + 1, oldBody[0][1]];
} else if (newDirection == 2) { //down
return [oldBody[0][0], oldBody[0][1] + 1];
} else if (newDirection == 3) { //left
return [oldBody[0][0] - 1, oldBody[0][1]];
}
}
function makeSnakeLonger() {
if (that.snake.length > that.snake.body.length) {
that.addToTail(oldBody[oldBody.length - 1]);
} else {
removeFromTail(oldBody[oldBody.length - 1]);
}
}
function removeFromTail(pos) {
that.board[pos[0]][pos[1]].setSnake(false);
}
function addNewHeadPos(pos) {
that.snake.body[0] = pos;
that.board[pos[0]][pos[1]].setSnake(true);
}
}
lose() {
this.lost = true;
}
}
class Field {
constructor(col, row) {
this.col = col;
this.row = row;
this.isFruit = false;
this.isSnake = false;
}
setFruit(bool) {
this.isFruit = bool;
}
setSnake(bool) {
this.isSnake = bool;
}
}
class Snake {
constructor() {
this.body = [];
this.length = 4;
}
eat() {
this.length++;
}
look(direction, board) {
let distances = {distToFruit: 0, distToWall: 0, distToBody: 0};
let xDiff = getXDiff(direction), yDiff = getYDiff(direction);
let pos = [this.body[0][0] + xDiff, this.body[0][1] + yDiff];
let dist = 1;
while (pos[0] > 0 && pos[0] < nrOfRows && pos[1] > 0 && pos[1] < nrOfCols) {
if (board[pos[0]][pos[1]].isFruit && distances.distToFruit == 0) distances.distToFruit = dist;
if (board[pos[0]][pos[1]].isSnake && distances.distToBody == 0) distances.distToBody = dist;
pos[0] += xDiff, pos[1] += yDiff;
dist++;
}
distances.distToWall = dist;
return distances;
function getXDiff(direction) {
if (direction == 5 || direction == 6 || direction == 7) return -1;
else if (direction == 1 || direction == 2 || direction == 3) return 1;
return 0;
}
function getYDiff(direction) {
if (direction == 7 || direction == 0 || direction == 1) return -1;
else if (direction == 3 || direction == 4 || direction == 5) return 1;
return 0;
}
}
}
class NeuralNetwork {
constructor(weights) {
this.layers = createLayers();
this.layers = addWeights(this.layers, weights);
function createLayers() {
let layers = [];
let nrOfNodesGlobal;
nodeNrs.forEach((nrOfNodes, lNr) => {
nrOfNodesGlobal = nrOfNodes;
layers[lNr] = [];
for (let i = 0; i < nrOfNodes; i++) {
let node = createNode(lNr);
layers[lNr][i] = node;
}
if (lNr != nodeNrs.length - 1)
layers[lNr].push(new Bias());
});
return layers;
function createNode(lNr) {
if (lNr == 0) return new InputLayerNode();
else if (lNr == nrOfNodesGlobal - 1) return new OutputLayerNode();
else return new HiddenLayerNode();
}
}
function addWeights(layers, weights) {
for (let lNr = 0; lNr < layers.length - 1; lNr++) {
let l = layers[lNr];
l.forEach((n1, nNr) => {
for (let n2Nr = 0; n2Nr < layers[lNr+1].length - 1; n2Nr++) { //not including bias of next layer
let n2 = layers[lNr+1][n2Nr];
let weight = weights[lNr][nNr][n2Nr];
let w = new Weight(n1, n2, weight);
n1.addWeight(w);
}
});
}
return layers;
}
}
getOutput(inputValues) {
let output = [];
this.layers[0].forEach((inputNeuron, nNr) => {
if (nNr != this.layers[0].length - 1)
inputNeuron.addToInput(inputValues[nNr]);
});
this.layers.forEach((l, lNr) => {
calcOutputs(l);
if (lNr != this.layers.length - 1) {
l.forEach(n => {
n.feedForward();
});
} else {
output = l.map(n => n.output);
}
});
return output;
function calcOutputs(layer) {
layer.forEach(n => n.output = n.activationFunction(n.summedInput, layer.map(N => N.summedInput)));
}
}
log() {
console.log(this.weights, this.nodes);
}
}
class Node {
constructor() {
this.weights = [];
this.summedInput = 0;
}
addWeight(w) {
this.weights.push(w);
}
addToInput(input) {
if (input == NaN)
console.log("A");
this.summedInput += input;
}
feedForward() {
this.weights.forEach((w, wNr) => {
let input = w.weight*this.output;
w.to.addToInput(input);
});
}
}
class Bias extends Node {
constructor() {
super();
this.output = 1;
}
activationFunction(x, allXs) {
return x;
}
}
class InputLayerNode extends Node {
constructor() {
super();
}
activationFunction(x, allXs) {
return x;
}
}
class HiddenLayerNode extends Node {
constructor() {
super();
}
activationFunction(x, allXs) {
return leakyReLU(x);
}
}
class OutputLayerNode extends Node {
constructor() {
super();
}
activationFunction(x, allXs) {
return softmax(x, allXs);
}
}
class Weight {
constructor(from, to, weight) {
this.from = from;
this.to = to;
this.weight = weight;
}
setWeight(newWeight) {
this.weight = weight;
}
}
function leakyReLU(x) {
if (x >= 0) return x;
else return 0.01*x;
}
function softmax(x, allXs) {
return Math.exp(x) / allXs.map(X => Math.exp(X)).reduce((a, b) => a+b);
}
<!DOCTYPE html>
<html>
<head>
<script src="https://cdnjs.cloudflare.com/ajax/libs/p5.js/0.8.0/p5.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/p5.js/0.8.0/addons/p5.dom.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/p5.js/0.8.0/addons/p5.sound.min.js"></script>
<link rel="stylesheet" type="text/css" href="style.css">
<meta charset="utf-8" />
</head>
<body>
<script src="sketch.js"></script>
</body>
</html>
It's not working that well but a few improvements should make it better...
If you have any suggestions for improvements of the code, please let me know!
I tried to fix it into steps as I said in comments,I hope I have no mistake :
let i = 0;
async function step(bestGameTurns, turn)
{
if (turn == bestGameTurns.length)
return;
let board = bestGameTurns[turn];
drawBoard(board);
let p = new Promise(resolve => setTimeout(() => step(bestGameTurns, turn+1), 500));
await p;
}
function drawBoard(board) {
//Draw the board using p5.js rect()'s
}
setInterval(async () => {
population.createNewGeneration();
console.log(i, population.avgFitness);
let bestGameTurns = population.bestIndividual.game.turns; //Array of boards
step(bestGameTurns, 0);
i++;
}, 1);

Javascript: scope effect despite order of execution

Please note: This is not a question about scope, per se. I understand that in order to make the code work, I should make a deep copy of the variable board rather than assigning var tboard = board. However, I am not clear why making a shallow copy has the effect I describe below.
I am experiencing something I find baffling. Basically, a global variable (board) gets altered and I have no clue how. board is initialized in the function NewGame() (which is called from select()) as an empty array. After it is initialized, nothing else is called until the user clicks a square on the board (assuming the user has selected Xs for simplicity). When that happens, the function playerMove() is called. The baffling thing is that console.log(board) at the top of playerMove() prints out an array that has an x is the clicked position and os everywhere else (ie not empty). This is bizarre because the board is empty at the end of select() (which called NewGame()) and nothing else should happen in between. To demonstrate this, I print out the function name at the top of each function and I print out the board variable in the select() function and playerMove() function to show that it changes despite nothing else being called. Please note that to get this behavior, refresh the page (otherwise the board variable starts out full of os). I think this must be somewhat an issue of scope (because I am not making a deep copy of board) but it's strange because I have no clue what is being called that is changing the variable before it gets printed out at the top of playerMove().
Here is the link to my pen and the code: http://codepen.io/joshlevy89/pen/MKjxop?editors=101
$(document).ready(function() {
var pSym; // player's symbol
var cSym; // computer's symbol
var board;
var whosMove; // can be "player" or "computer" or "neither"
var gameOver;
setup();
$("#newgame").on('click', '#X', select);
$("#newgame").on('click', '#O', select);
$("#restart").on('click', setup);
$("table").on('click', 'td', playerMove);
function playerMove()
{
console.log('playerMove');
console.log(board);
if (whosMove === "player")
{
var val = $(this).data('value');
$('#g' + val).text(pSym);
var arr = PositionToCoords(val);
board[arr[0]][arr[1]] = pSym;
var tboard = board;
var gc = gameCheck(tboard);
if (gc>=0)
{
endGame(gc);
setTimeout(function(){setup();}, 1000);
return;
}
whosMove = "computer";
computerMove();
}
}
function computerMove() {
console.log('computerMove');
//var p1 = Math.floor(Math.random() * 3);
//var p2 = Math.floor(Math.random() * 3);
var tboard = board;
var pos = chooseMove(tboard);
var arr = PositionToCoords(pos);
board[arr[0]][arr[1]] = cSym;
DrawPosition(arr[0], arr[1], cSym);
var tboard = board;
var gc = gameCheck(tboard);
if (gc>=0) {
endGame(gc);
setTimeout(function(){setup();}, 1000);
return;
}
whosMove = "player";
}
function chooseMove(inboard) {
console.log('chooseMove');
// get the possible moves
var moves=[];
var scores = [];
for (var i=1;i<10;i++) {
var arr = PositionToCoords(i);
if (inboard[arr[0]][arr[1]] === undefined) {
moves.push(i);
var tboard = inboard;
tboard[arr[0]][arr[1]] = cSym;
var gc = gameCheck(tboard);
scores.push(gc);
}
}
//console.log(moves);
//console.log(scores);
return moves[0]; // TEMPORARY
}
function endGame(gc) {
console.log('endGame');
var str;
if (gc===1) { // somebody won
if (whosMove==="player"){
str = "You Won!"
}
else {
str = "You Lost :(";
}
}
else if (gc === 0){//draw
str = "It's a draw."
}
html = '<div id="closer">' + str + '</div>';
$('#endgame').html(html);
}
function gameCheck(tboard) {
console.log('gameCheck');
// get symbol to check for
var sym;
if (whosMove === "player") {
sym = pSym;
} else {
sym = cSym;
}
// check if in a row
var hrow;
var vrow;
// check for horizonal row
for (var i = 0; i < 3; i++) {
hrow = true;
vrow = true;
for (var j = 0; j < 3; j++) {
if (tboard[i][j] !== sym) {
hrow = false;
}
if (tboard[j][i] !== sym) {
vrow = false;
}
}
if ((hrow) || (vrow)) {
return 1;
}
}
var fdrow = true;
var bdrow = true;
for (var i = 0; i < 3; i++) {
if (tboard[i][i] !== sym) {
fdrow = false;
}
if (tboard[i][2 - i] !== sym) {
bdrow = false;
}
}
if ((fdrow) || (bdrow)) {
return 1;
}
// otherwise, check if board is full
var full = true;
for (var i = 1; i < 10; i++) {
var arr = PositionToCoords(i);
if (tboard[arr[0]][arr[1]] === undefined) {
full = false;
break;
}
}
if (full === true) {
return 0;
}
// if neither 0 (tie) or win (1), return -1 (game not over)
return -1;
}
function select() {
console.log('select');
pSym = $(this).data('value');
$('#newgame').html('');
NewGame();
console.log(board);
}
function setup() {
console.log('select');
$('#endgame').html('');
html = '<div id="opener">Xs or Os? <div id="buttons">';
html += '<div id="X" data-value="X" class="btn btn-default">Xs</div>';
html += '<div id="O" data-value="O" class="btn btn-default">Os</div>';
html += '</div></div>';
$('#newgame').html(html);
}
function NewGame() {
console.log('NewGame');
$('td').empty();
board = new Array(3);
for (i = 0; i < 3; i++) {
board[i] = new Array(3)
};
if (pSym === "X") {
cSym = "O";
whosMove = "player";
} else {
cSym = "X";
whosMove = "computer";
computerMove();
}
}
function DrawPosition(p1, p2, sym) {
console.log('DrawPosition');
var pos = p1 * 3 + (p2 + 1);
$("#g" + pos).text(sym)
}
function PositionToCoords(pos) {
console.log('PositionToCoords');
var p1 = Math.ceil(pos / 3) - 1;
var p2 = ((pos - 1) % 3);
var arr = [p1, p2];
return arr;
}
});
Thanks in advance.
Simply add the break in the for loop fixes the problem. Am I missing anything?
function chooseMove(inboard) {
console.log('chooseMove');
// get the possible moves
var moves = [];
var scores = [];
for (var i = 1; i < 10; i++) {
var arr = PositionToCoords(i);
if (inboard[arr[0]][arr[1]] === undefined) {
moves.push(i);
var tboard = inboard;
tboard[arr[0]][arr[1]] = cSym;
var gc = gameCheck(tboard);
scores.push(gc);
break; // <<<<<<<<<<<< This break guarantees that the computer only makes one move
}
}
//console.log(moves);
//console.log(scores);
return moves[0]; // TEMPORARY
}

'Arc is not a constructor' error

I am getting an error saying Arc is not a constructor. I have checked my code and can't understand why.
/*
Exception: Arc is not a constructor
RouteFinder/this.getPairs#Scratchpad/8:72:6
#Scratchpad/8:5:3
*/
The other answers for this error suggest that this because Arc has previously been defined, but I cant find anywhere that it is. This is a big chunk of code, so scroll down for the error - it is commented where it is
var lats = [ 51.445371, 51.45526, 51.426765, 51.441304 ]
var lons = [ -0.077581, -0.113248, -0.13091, -0.060596 ]
var finder = new RouteFinder(lats, lons);
finder.getPairs();
var nodeList = ''
for(var count = 1; count < lats.length; count++) {
nodeList += count;
}
finder.permutation("", nodeList);
finder.removeDuplicateRoutes();
var shortestRoute = finder.getShortestRoute();
var finalRouteOrder = [];
shortestRoute.nodeList.forEach(function(node) {
finalRouteOrder.push(+node);
});
alert(finalRouteOrder);
var Route = function() {
this.totalWeight = 0;
this.nodeList = [];
};
var Node = function() {
this.lat = 0;
this.lon = 0;
this.number = 0;
};
var Arc = function() {
this.startNode = new Node();
this.endNode = new Node();
this.weight = 0;
};
function reverseString(initialString) {
var reversed = '';
for(var count = initialString.length -1; count > -1; count--) {
reversed += initialString.charAt(count);
}
return reversed;
}
function calcDistance(lat1, lng1, lat2, lng2) {
var earthRadius = 6371;
var dLat = (lat2 - lat1)/180*Math.PI;
var dLng = (lng2 - lng1)/180*Math.PI;
var a = Math.sin(dLat/2) * Math.sin(dLat/2) + Math.cos(lat1/180*Math.PI) * Math.cos(lat2/180*Math.PI) * Math.sin(dLng/2) * Math.sin(dLng/2);
var c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1-a));
var dist = earthRadius * c;
return dist;
}
function RouteFinder(lats, lons) {
this.latArray = lats;
this.lonArray = lons;
this.orders = [];
this.arcArray = [];
this.routes = [];
this.shortestRoute;
this.numOfPoints = lats.length - 1;
this.shortestRouteLength = -1;
this.getPairs = function() {
var timesLooped = 0;
for(var count1 = 0; count1 < this.numOfPoints; count1++) {
for(var count2 = 0; count2 < (this.numOfPoints - count1); count2++) {
//I get an error here for new Arc()
this.arcArray.push(new Arc());
this.arcArray[timesLooped].startNode = {
number: count1,
};
this.arcArray[timesLooped].endNode = {
number: this.numOfPoints - count2,
};
this.arcArray[timesLooped].weight = calcDistance(this.latArray[count1], this.lonArray[count1], this.latArray[this.numOfPoints - count2], this.lonArray[this.numOfPoints - count2]);
timesLooped++;
}
}
};
this.permutation = function(prefix, str) {
var n = str.length;
if(n === 0) this.orders.push('0' + prefix + '0');
else {
for(var i = 0; i <n; i++) {
this.permutation(prefix + str.charAt(i), str.substring(0, i) + str.substring(i + 1, n));
}
}
};
this.removeDuplicateRoutes = function() {
var numberOfPermutations = this.orders.length -1;
var temp;
var size;
var toRemove = [];
for(var count1 = 0; count1 < numberOfPermutations; count1++) {
for(var count2 = 0; count2 < (numberOfPermutations - count1); count2++) {
if(this.orders[count1] == reverseString(this.orders[numberOfPermutations - count2])) {
toRemove.push(count1);
}
}
}
size = toRemove.length;
for(var count3 = 0; count3 < size; count3++) {
temp = toRemove[size - 1- count3];
var index = this.orders.indexOf(temp);
if(index > -1) {
temp.splice(index, 1);
}
}
};
this.getShortestRoute = function() {
var routesMade = 0;
for(var routeNumber = 0; routeNumber < (this.orders.length -1); routeNumber++) {
this.routes.push(new Route());
this.routes[routesMade].totalWeight = 0;
for(var count1 = 0; count1 < this.orders[routeNumber].length; count1++) {
this.routes[routesMade].nodeList.push(+this.orders[routeNumber].charAt(count1));
}
for(var count2 = 1; count2 < this.orders[routeNumber].length; count2++) {
for(var count3 = 0; count3 < this.arcArray.length; count3++) {
if(this.routes[routesMade].nodeList[count2 - 1] === this.arcArray[count3].startNode.number) {
if(this.routes[routesMade].nodeList[count2] === this.arcArray[count3].endNode.number) {
this.routes[routesMade].totalWeight += this.arcArray[count3].weight;
}
} else if (this.routes[routesMade].nodeList[count2 - 1] === this.arcArray[count3].endNode.number) {
if(this.routes[routesMade].nodeList[count2] === this.arcArray[count3].startNode.number) {
this.routes[routesMade].totalWeight += this.arcArray[count3].weight;
}
}
}
}
if(!this.shortestRoute) {
this.shortestRoute = this.routes[routesMade];
} else if(this.routes[routesMade].totalWeight < this.shortestRoute.totalWeight) {
this.shortestRoute = this.routes[routesMade];
}
routesMade++;
}
return this.shortestRoute;
};
}
I'm tearing my hair out trying to work out the problem. Help is greatly appreciated, thanks!
This
var finder = new RouteFinder(lats, lons);
gets executed before Arc variable gets its value (function). Thus at the moment of RouteFinder call that Arc variable is undefined and cannot be used as a constructor.
Update: it is about finder.getPairs(); actually where you try to call that new Arc();
You need to have Route, Node, and Arc like this:
function Route() {
this.totalWeight = 0;
this.nodeList = [];
}
function Node() {
this.lat = 0;
this.lon = 0;
this.number = 0;
}
function Arc() {
this.startNode = new Node();
this.endNode = new Node();
this.weight = 0;
}
The issue is that Arc is not yet defined. Either move your function expression assignment (var Arc = function ...) to the top of your script or convert them to function definition statements like this
function Arc() {
this.startNode = new Node();
this.endNode = new Node();
this.weight = 0;
}
Statements are hoisted and their order does not matter, but assignment to var happens in the order they appear in the file (the declaration is hoisted, but the assignment isn't).
Same goes for your Route and Node functions.
Read more about var hoisting on MDN.

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