source code
/* The Computer Language Benchmarks Game
https://salsa.debian.org/benchmarksgame-team/benchmarksgame/
Naive transliteration from Michael Ferguson's Chapel program
contributed by Isaac Gouy
*/
const PI = Math.PI;
const SOLAR_MASS = 4 * PI * PI;
const DAYS_PER_YEAR = 365.24;
class Body {
constructor(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;
}
}
function offsetMomentum(bodies) {
let px = py = pz = 0;
for (const b of bodies) {
px += b.vx * b.mass;
py += b.vy * b.mass;
pz += b.vz * b.mass;
}
const b = bodies[0];
b.vx = -px / SOLAR_MASS;
b.vy = -py / SOLAR_MASS;
b.vz = -pz / SOLAR_MASS;
}
function energy(bodies) {
let e = 0;
const numBodies = bodies.length;
for (let i = 0; i < numBodies; i++) {
const b = bodies[i];
const sq = b.vx * b.vx + b.vy * b.vy + b.vz * b.vz;
e += 0.5 * bodies[i].mass * sq;
for (let j = i + 1; j < numBodies; j++) {
const dx = b.x - bodies[j].x;
const dy = b.y - bodies[j].y;
const dz = b.z - bodies[j].z;
const sq = dx * dx + dy * dy + dz * dz;
e -= (b.mass * bodies[j].mass) / Math.sqrt(sq)
}
}
return e;
}
function advance(bodies, dt) {
const numBodies = bodies.length;
for (let i = 0; i < numBodies; i++) {
for (let j = i + 1; j < numBodies; j++) {
const dx = bodies[i].x - bodies[j].x;
const dy = bodies[i].y - bodies[j].y;
const dz = bodies[i].z - bodies[j].z;
const dposNormSq = dx**2 + dy**2 + dz**2;
const mag = dt / (dposNormSq * Math.sqrt(dposNormSq));
const mj = bodies[j].mass * mag;
bodies[i].vx -= dx * mj;
bodies[i].vy -= dy * mj;
bodies[i].vz -= dz * mj;
const mi = bodies[i].mass * mag;
bodies[j].vx += dx * mi;
bodies[j].vy += dy * mi;
bodies[j].vz += dz * mi;
}
}
for (const b of bodies) {
b.x += b.vx * dt;
b.y += b.vy * dt;
b.z += b.vz * dt;
}
}
function nbody(n) {
const bodies = [
// sun
new Body(0.0, 0.0, 0.0, 0.0, 0.0, 0.0, SOLAR_MASS),
// jupiter
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
),
// saturn
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
),
// uranus
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
),
// neptune
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
),
];
offsetMomentum(bodies);
console.log(energy(bodies).toFixed(9));
for (let i = 0; i < n; i++) {
advance(bodies,0.01);
}
console.log(energy(bodies).toFixed(9));
}
const n = +process.argv[2];
// in-process warmup
for (let i = 0; i < 3000; ++i) {
nbody(n);
}
// mtime side-effect
const fs = require("fs");
fs.closeSync(fs.openSync('./one', 'w'));
nbody(n);
// mtime side-effect
fs.closeSync(fs.openSync('./two', 'w'));
notes, command-line, and program output
NOTES:
64-bit Ubuntu quad core
v23.0.0
Wed, 23 Oct 2024 00:20:51 GMT
MAKE:
cp -L startup.node startup.js
0.20s to complete and log all make actions
COMMAND LINE:
/opt/src/node-v23.0.0/bin/node startup.js 200000
(TRUNCATED) PROGRAM OUTPUT:
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