/* The Great Computer Language Shootout   http://shootout.alioth.debian.org/   contributed by Isaac Gouy */var PI = 3.141592653589793;var SOLAR_MASS = 4 * PI * PI;var DAYS_PER_YEAR = 365.24;function Body(x,y,z,vx,vy,vz,mass){   this.x = x;   this.y = y;   this.z = z;   this.vx = vx;   this.vy = vy;   this.vz = vz;   this.mass = mass;}Body.prototype.offsetMomentum = function(px,py,pz) {   this.vx = -px / SOLAR_MASS;   this.vy = -py / SOLAR_MASS;   this.vz = -pz / SOLAR_MASS;   return this;}function Jupiter(){   return new Body(      4.84143144246472090e+00,      -1.16032004402742839e+00,      -1.03622044471123109e-01,      1.66007664274403694e-03 * DAYS_PER_YEAR,      7.69901118419740425e-03 * DAYS_PER_YEAR,      -6.90460016972063023e-05 * DAYS_PER_YEAR,      9.54791938424326609e-04 * SOLAR_MASS   );}function Saturn(){   return new Body(      8.34336671824457987e+00,      4.12479856412430479e+00,      -4.03523417114321381e-01,      -2.76742510726862411e-03 * DAYS_PER_YEAR,      4.99852801234917238e-03 * DAYS_PER_YEAR,      2.30417297573763929e-05 * DAYS_PER_YEAR,      2.85885980666130812e-04 * SOLAR_MASS   );}function Uranus(){   return new Body(      1.28943695621391310e+01,      -1.51111514016986312e+01,      -2.23307578892655734e-01,      2.96460137564761618e-03 * DAYS_PER_YEAR,      2.37847173959480950e-03 * DAYS_PER_YEAR,      -2.96589568540237556e-05 * DAYS_PER_YEAR,      4.36624404335156298e-05 * SOLAR_MASS   );}function Neptune(){   return new Body(      1.53796971148509165e+01,      -2.59193146099879641e+01,      1.79258772950371181e-01,      2.68067772490389322e-03 * DAYS_PER_YEAR,      1.62824170038242295e-03 * DAYS_PER_YEAR,      -9.51592254519715870e-05 * DAYS_PER_YEAR,      5.15138902046611451e-05 * SOLAR_MASS   );}function Sun(){   return new Body(0.0, 0.0, 0.0, 0.0, 0.0, 0.0, SOLAR_MASS);}function NBodySystem(bodies){   this.bodies = bodies;   var px = 0.0;   var py = 0.0;   var pz = 0.0;   var size = this.bodies.length;   for (var i=0; i<size; i++){      var b = this.bodies[i];      var m = b.mass;      px += b.vx * m;      py += b.vy * m;      pz += b.vz * m;   }   this.bodies[0].offsetMomentum(px,py,pz);}NBodySystem.prototype.advance = function(dt){   var dx, dy, dz, distance, mag;   var size = this.bodies.length;   for (var i=0; i<size; i++) {      var bodyi = this.bodies[i];      for (var j=i+1; j<size; j++) {         var bodyj = this.bodies[j];         dx = bodyi.x - bodyj.x;         dy = bodyi.y - bodyj.y;         dz = bodyi.z - bodyj.z;         distance = Math.sqrt(dx*dx + dy*dy + dz*dz);         mag = dt / (distance * distance * distance);         bodyi.vx -= dx * bodyj.mass * mag;         bodyi.vy -= dy * bodyj.mass * mag;         bodyi.vz -= dz * bodyj.mass * mag;         bodyj.vx += dx * bodyi.mass * mag;         bodyj.vy += dy * bodyi.mass * mag;         bodyj.vz += dz * bodyi.mass * mag;      }   }   for (var i=0; i<size; i++) {      var body = this.bodies[i];      body.x += dt * body.vx;      body.y += dt * body.vy;      body.z += dt * body.vz;   }}NBodySystem.prototype.energy = function(){   var dx, dy, dz, distance;   var e = 0.0;   var size = this.bodies.length;   for (var i=0; i<size; i++) {      var bodyi = this.bodies[i];      e += 0.5 * bodyi.mass *         ( bodyi.vx * bodyi.vx         + bodyi.vy * bodyi.vy         + bodyi.vz * bodyi.vz );      for (var j=i+1; j<size; j++) {         var bodyj = this.bodies[j];         dx = bodyi.x - bodyj.x;         dy = bodyi.y - bodyj.y;         dz = bodyi.z - bodyj.z;         distance = Math.sqrt(dx*dx + dy*dy + dz*dz);         e -= (bodyi.mass * bodyj.mass) / distance;      }   }   return e;}var ret;for ( var n = 3; n <= 24; n *= 2 ) {    (function(){        var bodies = new NBodySystem( Array(           Sun(),Jupiter(),Saturn(),Uranus(),Neptune()        ));        var max = n * 100;                ret = bodies.energy();        for (var i=0; i<max; i++){            bodies.advance(0.01);        }        ret = bodies.energy();    })();}