Участник:StarfloFr

Материал из Department of Theoretical and Applied Mechanics
Перейти к: навигация, поиск

КОД

<!DOCTYPE html> <html lang="ru"> <head> 

  <title>Модель броуновского движения</title>

<meta charset="UTF-8">


</head>

<style> canvas { border: 1px solid black; } .pr {

border-bottom :1px solid #a2a9b1;

</style> <body onload = "start();" >


Модель Броуновского движения

Описание

Модель Броуновского движения с изоброжением траектории. Работа сделана на языке программирования JavaScript.

Исполнитель: Никита Натальин.

Группа:3630103/90001


Визуализация

   

   <input type="text" id="size" value="500">
   
   <input type="button" value="chaneg size" onclick="changeSize();">
   

   <input type="text" id="addCount" value="10">
   <input type="button" value="add" onclick="add();">
   
   <input type="button" value="delete" onclick="del();">
   


   <input type="text" id="weight" value="500">
   <input type="button" value="weight" onclick="weight();">
   


   <input type="button" value="slowly" onclick="slowly();">
   <input type="button" value="faster" onclick="faster();">
  
   

   
   
    
   <label><input type="checkbox" id="color" checked>color</label>

<canvas id="GG" width="500" height="500"></canvas> <script>

class Ball { constructor(x, y, r, vx, vy,color){ this.x = x; this.y = y; this.r = r; this.vx = vy; this.vy = vx;

this.calculateMass();

this.color = color; }

calculateMass() { this.m = (this.r * this.r * this.r)/50 ; }

getVx() { return this.vx * Math.pow(2, timeSpeed); }

getVy() { return this.vy * Math.pow(2, timeSpeed); }

move() { this.x += this.getVx(); this.y += this.getVy(); }

}

var count = 50;

var MAX_SPEED = 20; var MIN_RADIUS = 100; var MAX_RADIUS = 100; var WIDTH = 10000;

var timeSpeed = 0;

var balls = [];

var canvas; var ctx; var T = 300; var pathx = []; var pathy = [];

function random(min, max) { return Math.random() * (max - min) + min; }

function move() {

for (var i = 0; i < count; i++) { var ball = balls[i];

if (ball.x < ball.r && ball.vx < 0) ball.vx *=-1; if (ball.x > WIDTH-ball.r && ball.vx > 0) ball.vx *=-1; if (ball.y < ball.r && ball.vy < 0) ball.vy *=-1; if (ball.y > WIDTH-ball.r && ball.vy > 0) ball.vy *=-1;

for (var j = i + 1; j < count; j++) { var ball2= balls[j]; var z = (ball.x - ball2.x) * (ball.getVx() - ball2.getVx()) + (ball.y - ball2.y) * (ball.getVy() - ball2.getVy()); var l = Math.pow(ball.getVx() - ball2.getVx(), 2) + Math.pow(ball.getVy() - ball2.getVy(), 2); var m = Math.pow(ball.x - ball2.x, 2) + Math.pow(ball.y - ball2.y, 2) - Math.pow(ball.r + ball2.r, 2);

var d = z*z - l*m;

var t0 = -(z + Math.sqrt(d)) / l;

var p = Math.pow(ball.x - ball2.x, 2) + Math.pow(ball.y - ball2.y, 2);

if (t0 >= 0 && t0 <= 1 || p < Math.pow(ball.r + ball2.r, 2)) { ball.x += t0 * ball.getVx(); ball.y += t0 * ball.getVy(); ball2.x += t0 * ball2.getVx(); ball2.y += t0 * ball2.getVy();

var px = ball.x - ball2.x; var py = ball.y - ball2.y;

var q = 2 * (px * (ball2.vx - ball.vx) + py * (ball2.vy - ball.vy))

var dvx = q * px / (Math.pow(px, 2) + Math.pow(py,2)) * ball.m * ball2.m / (ball.m + ball2.m); var dvy = q * py / (Math.pow(px, 2) + Math.pow(py,2)) * ball.m * ball2.m / (ball.m + ball2.m); var k = 1.38 * Math.pow(10,-23);

ball.vx += dvx / ball.m; ball.vy += dvy / ball.m; ball2.vx -= dvx / ball2.m; ball2.vy -= dvy / ball2.m;

}

}

ball.move(); }


draw(); }


function draw() { ctx.clearRect(0, 0, canvas.width, canvas.height);

var c = canvas.width / WIDTH;

for (var i = 0; i < count; i++) { var ball= balls[i]; ctx.beginPath(); ctx.arc(ball.x * c, ball.y * c, ball.r * c, 0, 2 * Math.PI, false);

if (document.getElementById('color').checked) ctx.fillStyle = ball.color; else ctx.fillStyle = 'blue';

ctx.fill();


} drawPath(); }

function start() { balls[0]= new Ball( WIDTH/2 , WIDTH/2, 500, 0, 0,'red'); for (var i = 1; i < count; i++) { var r = random(MIN_RADIUS, MAX_RADIUS); balls[i] = new Ball(random(r, WIDTH - r), random(r, WIDTH - r), r, random(-MAX_SPEED, MAX_SPEED), random(-MAX_SPEED, MAX_SPEED),'blue');

}

canvas = document.getElementById('GG'); ctx = canvas.getContext('2d');

setInterval(move, 1); }

function weight() {

var r = parseInt(document.getElementById('weight').value); if (r > WIDTH / 2 || r < 50) return;

var oldMass = balls[0].m; balls[0].r = r; balls[0].calculateMass();

balls[0].vx *= Math.sqrt(oldMass / balls[0].m); balls[0].vy *= Math.sqrt(oldMass / balls[0].m);

if (balls[0].x > WIDTH - r) balls[0].x = WIDTH - r; if (balls[0].x < r) balls[0].x = r; if (balls[0].y > WIDTH - r) balls[0].y = WIDTH - r; if (balls[0].y < r) balls[0].y = r;

}

function changeSize() { canvas.width = document.getElementById('size').value; canvas.height = document.getElementById('size').value; } var tander = 0;

function drawPath() { tander++; if(tander === 5){ tander=0; if ( pathx.length>=1000){ pathx.shift(); pathy.shift(); }

var c = canvas.width / WIDTH; pathx.push( balls[0].x*c); pathy.push( balls[0].y*c); } ctx.beginPath(); 

           ctx.lineWidth = 2;

ctx.strokeStyle = 'Black'; 

           ctx.moveTo(pathx[0], pathy[0]);

for (i=1;i<pathx.length; i++) { ctx.lineTo(pathx[i], pathy[i]); }

ctx.stroke(); }


function add() { var k = parseInt(document.getElementById('addCount').value); k = Math.min(k , 250 - balls.length); for (var i = 0; i < k; i++) { var r = random(MIN_RADIUS, MAX_RADIUS); balls[count + i] = new Ball(random(r, WIDTH - r), random(r, WIDTH - r), r, random(-MAX_SPEED, MAX_SPEED), random(-MAX_SPEED, MAX_SPEED));

} count += k; }

function del() { var k = Math.min(count - 1, parseInt(document.getElementById('addCount').value)); balls = balls.slice(0, count - k); count -= k; }

function slowly() { if (timeSpeed > -3) timeSpeed--; }

function faster() { if (timeSpeed < 3) timeSpeed++; }

</script> </body> </html>

Источник — «http://tm.spbstu.ru/?title=Участник:StarfloFr&oldid=56124»