chrome/test/data/dromaeo/tests/sunspider-access-nbody.html

   1 <html>
   2 <head>
   3 <script src="../htmlrunner.js"></script>
   4 <script>
   5 /* The Great Computer Language Shootout
   6    http://shootout.alioth.debian.org/
   7    contributed by Isaac Gouy */
   8
   9 var PI = 3.141592653589793;
  10 var SOLAR_MASS = 4 * PI * PI;
  11 var DAYS_PER_YEAR = 365.24;
  12
  13 function Body(x,y,z,vx,vy,vz,mass){
  14    this.x = x;
  15    this.y = y;
  16    this.z = z;
  17    this.vx = vx;
  18    this.vy = vy;
  19    this.vz = vz;
  20    this.mass = mass;
  21 }
  22
  23 Body.prototype.offsetMomentum = function(px,py,pz) {
  24    this.vx = -px / SOLAR_MASS;
  25    this.vy = -py / SOLAR_MASS;
  26    this.vz = -pz / SOLAR_MASS;
  27    return this;
  28 }
  29
  30 function Jupiter(){
  31    return new Body(
  32       4.84143144246472090e+00,
  33       -1.16032004402742839e+00,
  34       -1.03622044471123109e-01,
  35       1.66007664274403694e-03 * DAYS_PER_YEAR,
  36       7.69901118419740425e-03 * DAYS_PER_YEAR,
  37       -6.90460016972063023e-05 * DAYS_PER_YEAR,
  38       9.54791938424326609e-04 * SOLAR_MASS
  39    );
  40 }
  41
  42 function Saturn(){
  43    return new Body(
  44       8.34336671824457987e+00,
  45       4.12479856412430479e+00,
  46       -4.03523417114321381e-01,
  47       -2.76742510726862411e-03 * DAYS_PER_YEAR,
  48       4.99852801234917238e-03 * DAYS_PER_YEAR,
  49       2.30417297573763929e-05 * DAYS_PER_YEAR,
  50       2.85885980666130812e-04 * SOLAR_MASS
  51    );
  52 }
  53
  54 function Uranus(){
  55    return new Body(
  56       1.28943695621391310e+01,
  57       -1.51111514016986312e+01,
  58       -2.23307578892655734e-01,
  59       2.96460137564761618e-03 * DAYS_PER_YEAR,
  60       2.37847173959480950e-03 * DAYS_PER_YEAR,
  61       -2.96589568540237556e-05 * DAYS_PER_YEAR,
  62       4.36624404335156298e-05 * SOLAR_MASS
  63    );
  64 }
  65
  66 function Neptune(){
  67    return new Body(
  68       1.53796971148509165e+01,
  69       -2.59193146099879641e+01,
  70       1.79258772950371181e-01,
  71       2.68067772490389322e-03 * DAYS_PER_YEAR,
  72       1.62824170038242295e-03 * DAYS_PER_YEAR,
  73       -9.51592254519715870e-05 * DAYS_PER_YEAR,
  74       5.15138902046611451e-05 * SOLAR_MASS
  75    );
  76 }
  77
  78 function Sun(){
  79    return new Body(0.0, 0.0, 0.0, 0.0, 0.0, 0.0, SOLAR_MASS);
  80 }
  81
  82
  83 function NBodySystem(bodies){
  84    this.bodies = bodies;
  85    var px = 0.0;
  86    var py = 0.0;
  87    var pz = 0.0;
  88    var size = this.bodies.length;
  89    for (var i=0; i<size; i++){
  90       var b = this.bodies[i];
  91       var m = b.mass;
  92       px += b.vx * m;
  93       py += b.vy * m;
  94       pz += b.vz * m;
  95    }
  96    this.bodies[0].offsetMomentum(px,py,pz);
  97 }
  98
  99 NBodySystem.prototype.advance = function(dt){
 100    var dx, dy, dz, distance, mag;
 101    var size = this.bodies.length;
 102
 103    for (var i=0; i<size; i++) {
 104       var bodyi = this.bodies[i];
 105       for (var j=i+1; j<size; j++) {
 106          var bodyj = this.bodies[j];
 107          dx = bodyi.x - bodyj.x;
 108          dy = bodyi.y - bodyj.y;
 109          dz = bodyi.z - bodyj.z;
 110
 111          distance = Math.sqrt(dx*dx + dy*dy + dz*dz);
 112          mag = dt / (distance * distance * distance);
 113
 114          bodyi.vx -= dx * bodyj.mass * mag;
 115          bodyi.vy -= dy * bodyj.mass * mag;
 116          bodyi.vz -= dz * bodyj.mass * mag;
 117
 118          bodyj.vx += dx * bodyi.mass * mag;
 119          bodyj.vy += dy * bodyi.mass * mag;
 120          bodyj.vz += dz * bodyi.mass * mag;
 121       }
 122    }
 123
 124    for (var i=0; i<size; i++) {
 125       var body = this.bodies[i];
 126       body.x += dt * body.vx;
 127       body.y += dt * body.vy;
 128       body.z += dt * body.vz;
 129    }
 130 }
 131
 132 NBodySystem.prototype.energy = function(){
 133    var dx, dy, dz, distance;
 134    var e = 0.0;
 135    var size = this.bodies.length;
 136
 137    for (var i=0; i<size; i++) {
 138       var bodyi = this.bodies[i];
 139
 140       e += 0.5 * bodyi.mass *
 141          ( bodyi.vx * bodyi.vx
 142          + bodyi.vy * bodyi.vy
 143          + bodyi.vz * bodyi.vz );
 144
 145       for (var j=i+1; j<size; j++) {
 146          var bodyj = this.bodies[j];
 147          dx = bodyi.x - bodyj.x;
 148          dy = bodyi.y - bodyj.y;
 149          dz = bodyi.z - bodyj.z;
 150
 151          distance = Math.sqrt(dx*dx + dy*dy + dz*dz);
 152          e -= (bodyi.mass * bodyj.mass) / distance;
 153       }
 154    }
 155    return e;
 156 }
 157
 158 window.onload = function(){ startTest("sunspider-access-nbody", '38cd3387');
 159
 160 var ret;
 161
 162 test( "N-Body", function(){
 163         for ( var n = 3; n <= 6; n *= 2 ) {
 164         var bodies = new NBodySystem( Array(
 165            Sun(),Jupiter(),Saturn(),Uranus(),Neptune()
 166         ));
 167         var max = n * 100;
 168
 169         ret = bodies.energy();
 170         for (var i=0; i<max; i++){
 171                 bodies.advance(0.01);
 172         }
 173         ret = bodies.energy();
 174         }
 175 });
 176
 177 endTest(); };
 178 </script>
 179 </head>
 180 <body></body>
 181 </html>