source code
// The Computer Language Benchmarks Game
// https://salsa.debian.org/benchmarksgame-team/benchmarksgame/
//
// contributed by Valentin Kraevskiy
// modified by Peter Kese
let pi = 3.141592653589793
let daysPerYear = 365.24
let solarMass = 4.0 * pi ** 2.0
type Body = {
mutable X: float; mutable Y: float; mutable Z: float
Mass: float
mutable VX: float; mutable VY: float; mutable VZ: float
}
let planets = [|
{ // jupiter
X = 4.84143144246472090e+00
Y = -1.16032004402742839e+00
Z = -1.03622044471123109e-01
VX = 1.66007664274403694e-03 * daysPerYear
VY = 7.69901118419740425e-03 * daysPerYear
VZ = -6.90460016972063023e-05 * daysPerYear
Mass = 9.54791938424326609e-04 * solarMass }
{ // saturn
X = 8.34336671824457987e+00
Y = 4.12479856412430479e+00
Z = -4.03523417114321381e-01
VX = -2.76742510726862411e-03 * daysPerYear
VY = 4.99852801234917238e-03 * daysPerYear
VZ = 2.30417297573763929e-05 * daysPerYear
Mass = 2.85885980666130812e-04 * solarMass }
{ // uranus
X = 1.28943695621391310e+01
Y = -1.51111514016986312e+01
Z = -2.23307578892655734e-01
VX = 2.96460137564761618e-03 * daysPerYear
VY = 2.37847173959480950e-03 * daysPerYear
VZ = -2.96589568540237556e-05 * daysPerYear
Mass = 4.36624404335156298e-05 * solarMass }
{ // neptune
X = 1.53796971148509165e+01
Y = -2.59193146099879641e+01
Z = 1.79258772950371181e-01
VX = 2.68067772490389322e-03 * daysPerYear
VY = 1.62824170038242295e-03 * daysPerYear
VZ = -9.51592254519715870e-05 * daysPerYear
Mass = 5.15138902046611451e-05 * solarMass }
|]
let bodies = [
let svx,svy,svz = // sun momentum
planets |> Array.fold (fun (x, y, z) body ->
let c = body.Mass / solarMass
(x - c * body.VX, y - c * body.VY, z - c * body.VZ))
(0.0, 0.0, 0.0)
yield { X=0.0; Y=0.0; Z=0.0; VX=svx; VY=svy; VZ=svz; Mass=solarMass } // sun
yield! planets
]
type System = {
bodies: Body list
pairs: struct (Body * Body) list
}
let system = {
bodies=bodies
pairs=[ for i in 0..bodies.Length-2 do
for j in i+1..bodies.Length-1 do
struct (bodies.[i], bodies.[j]) ]
}
let simulate {bodies=bodies; pairs=pairs} repetitions dt =
for _ in 1..repetitions do
// calculate pairwise forces
for b1,b2 in pairs do
let dx,dy,dz = b1.X-b2.X, b1.Y-b2.Y, b1.Z-b2.Z
let dist2 = dx*dx + dy*dy + dz*dz
let mag = dt / (dist2 * sqrt dist2)
let mag2 = b2.Mass * mag
let mag1 = b1.Mass * mag
b1.VX <- b1.VX - mag2 * dx
b1.VY <- b1.VY - mag2 * dy
b1.VZ <- b1.VZ - mag2 * dz
b2.VX <- b2.VX + mag1 * dx
b2.VY <- b2.VY + mag1 * dy
b2.VZ <- b2.VZ + mag1 * dz
// move bodies
for body in bodies do
body.X <- body.X + dt * body.VX
body.Y <- body.Y + dt * body.VY
body.Z <- body.Z + dt * body.VZ
let energy system =
let ePlanets = system.bodies |> List.fold (fun e b ->
e + 0.5 * b.Mass * (b.VX*b.VX + b.VY*b.VY + b.VZ*b.VZ)) 0.0
let ePairs = system.pairs |> List.fold (fun e struct (b1,b2) ->
let dx,dy,dz = b1.X-b2.X, b1.Y-b2.Y, b1.Z-b2.Z
let dist = sqrt (dx*dx + dy*dy + dz*dz)
e + b1.Mass * b2.Mass / dist) 0.0
ePlanets - ePairs
[<EntryPoint>]
let main args =
let repetitions = try int args.[0] with _ -> 20000000
let e0 = energy system
simulate system repetitions 0.01
printf "%.9f\n%.9f\n" e0 (energy system)
0
notes, command-line, and program output
NOTES:
64-bit Ubuntu quad core
.NET SDK 8.0.200
Host Version: 8.0.2
Commit: 1381d5ebd2
<ServerGarbageCollection>true
F# 8.0
Wed, 06 Mar 2024 20:42:02 GMT
MAKE:
cp nbody.fsharpcore-4.fsharpcore Program.fs
cp Include/fsharpcore/tmp.fsproj .
mkdir obj
cp Include/fsharpcore/project.assets.json ./obj
/usr/bin/dotnet build -c Release --no-restore --no-self-contained -r linux-x64
MSBuild version 17.9.4+90725d08d for .NET
tmp -> /home/dunham/all-benchmarksgame/benchmarksgame_i53330/nbody/tmp/bin/Release/net8.0/linux-x64/tmp.dll
Build succeeded.
0 Warning(s)
0 Error(s)
Time Elapsed 00:00:07.52
10.00s to complete and log all make actions
COMMAND LINE:
./bin/Release/net8.0/linux-x64/tmp 50000000
PROGRAM OUTPUT:
-0.169075164
-0.169059907