testing/performance/talos/page_load_test/jss/real-nbody-2.html

   1 <html><head>
   2 <!-- MOZ_INSERT_CONTENT_HOOK -->
   3 <script src = runner.js></script>
   4 <script>
   5 var onlyName = 'N-Body', onlyNum = 4;
   6 function thisTest() {
   7
   8 /* The Great Computer Language Shootout
   9    http://shootout.alioth.debian.org/
  10    contributed by Isaac Gouy */
  11
  12 var PI = 3.141592653589793;
  13 var SOLAR_MASS = 4 * PI * PI;
  14 var DAYS_PER_YEAR = 365.24;
  15
  16 function Body(x,y,z,vx,vy,vz,mass){
  17    this.x = x;
  18    this.y = y;
  19    this.z = z;
  20    this.vx = vx;
  21    this.vy = vy;
  22    this.vz = vz;
  23    this.mass = mass;
  24 }
  25
  26 Body.prototype.offsetMomentum = function(px,py,pz) {
  27    this.vx = -px / SOLAR_MASS;
  28    this.vy = -py / SOLAR_MASS;
  29    this.vz = -pz / SOLAR_MASS;
  30    return this;
  31 }
  32
  33 function Jupiter(){
  34    return new Body(
  35       4.84143144246472090e+00,
  36       -1.16032004402742839e+00,
  37       -1.03622044471123109e-01,
  38       1.66007664274403694e-03 * DAYS_PER_YEAR,
  39       7.69901118419740425e-03 * DAYS_PER_YEAR,
  40       -6.90460016972063023e-05 * DAYS_PER_YEAR,
  41       9.54791938424326609e-04 * SOLAR_MASS
  42    );
  43 }
  44
  45 function Saturn(){
  46    return new Body(
  47       8.34336671824457987e+00,
  48       4.12479856412430479e+00,
  49       -4.03523417114321381e-01,
  50       -2.76742510726862411e-03 * DAYS_PER_YEAR,
  51       4.99852801234917238e-03 * DAYS_PER_YEAR,
  52       2.30417297573763929e-05 * DAYS_PER_YEAR,
  53       2.85885980666130812e-04 * SOLAR_MASS
  54    );
  55 }
  56
  57 function Uranus(){
  58    return new Body(
  59       1.28943695621391310e+01,
  60       -1.51111514016986312e+01,
  61       -2.23307578892655734e-01,
  62       2.96460137564761618e-03 * DAYS_PER_YEAR,
  63       2.37847173959480950e-03 * DAYS_PER_YEAR,
  64       -2.96589568540237556e-05 * DAYS_PER_YEAR,
  65       4.36624404335156298e-05 * SOLAR_MASS
  66    );
  67 }
  68
  69 function Neptune(){
  70    return new Body(
  71       1.53796971148509165e+01,
  72       -2.59193146099879641e+01,
  73       1.79258772950371181e-01,
  74       2.68067772490389322e-03 * DAYS_PER_YEAR,
  75       1.62824170038242295e-03 * DAYS_PER_YEAR,
  76       -9.51592254519715870e-05 * DAYS_PER_YEAR,
  77       5.15138902046611451e-05 * SOLAR_MASS
  78    );
  79 }
  80
  81 function Sun(){
  82    return new Body(0.0, 0.0, 0.0, 0.0, 0.0, 0.0, SOLAR_MASS);
  83 }
  84
  85
  86 function NBodySystem(bodies){
  87    this.bodies = bodies;
  88    var px = 0.0;
  89    var py = 0.0;
  90    var pz = 0.0;
  91    var size = this.bodies.length;
  92    for (var i=0; i<size; i++){
  93       var b = this.bodies[i];
  94       var m = b.mass;
  95       px += b.vx * m;
  96       py += b.vy * m;
  97       pz += b.vz * m;
  98    }
  99    this.bodies[0].offsetMomentum(px,py,pz);
 100 }
 101
 102 NBodySystem.prototype.advance = function(dt){
 103    var dx, dy, dz, distance, mag;
 104    var size = this.bodies.length;
 105
 106    for (var i=0; i<size; i++) {
 107       var bodyi = this.bodies[i];
 108       for (var j=i+1; j<size; j++) {
 109          var bodyj = this.bodies[j];
 110          dx = bodyi.x - bodyj.x;
 111          dy = bodyi.y - bodyj.y;
 112          dz = bodyi.z - bodyj.z;
 113
 114          distance = Math.sqrt(dx*dx + dy*dy + dz*dz);
 115          mag = dt / (distance * distance * distance);
 116
 117          bodyi.vx -= dx * bodyj.mass * mag;
 118          bodyi.vy -= dy * bodyj.mass * mag;
 119          bodyi.vz -= dz * bodyj.mass * mag;
 120
 121          bodyj.vx += dx * bodyi.mass * mag;
 122          bodyj.vy += dy * bodyi.mass * mag;
 123          bodyj.vz += dz * bodyi.mass * mag;
 124       }
 125    }
 126
 127    for (var i=0; i<size; i++) {
 128       var body = this.bodies[i];
 129       body.x += dt * body.vx;
 130       body.y += dt * body.vy;
 131       body.z += dt * body.vz;
 132    }
 133 }
 134
 135 NBodySystem.prototype.energy = function(){
 136    var dx, dy, dz, distance;
 137    var e = 0.0;
 138    var size = this.bodies.length;
 139
 140    for (var i=0; i<size; i++) {
 141       var bodyi = this.bodies[i];
 142
 143       e += 0.5 * bodyi.mass *
 144          ( bodyi.vx * bodyi.vx
 145          + bodyi.vy * bodyi.vy
 146          + bodyi.vz * bodyi.vz );
 147
 148       for (var j=i+1; j<size; j++) {
 149          var bodyj = this.bodies[j];
 150          dx = bodyi.x - bodyj.x;
 151          dy = bodyi.y - bodyj.y;
 152          dz = bodyi.z - bodyj.z;
 153
 154          distance = Math.sqrt(dx*dx + dy*dy + dz*dz);
 155          e -= (bodyi.mass * bodyj.mass) / distance;
 156       }
 157    }
 158    return e;
 159 }
 160
 161 startTest("real-nbody");
 162
 163 var ret;
 164
 165 for ( var n = 2; n <= 16; n *= 2 ) (function(n){
 166         test( "N-Body", n, function(){
 167                 var bodies = new NBodySystem( Array(
 168                    Sun(),Jupiter(),Saturn(),Uranus(),Neptune()
 169                 ));
 170                 var max = n * 100;
 171
 172                 ret = bodies.energy();
 173                 for (var i=0; i<max; i++){
 174                         bodies.advance(0.01);
 175                 }
 176                 ret = bodies.energy();
 177         });
 178 })(n);
 179
 180 endTest();
 181 }
 182 </script>
 183 <body onload="thisTest()"></body></html>