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| 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", ''); |
| 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> |
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