luau/bench/tests/shootout/n-body.lua
Arseny Kapoulkine 46110524ef Sync to upstream/release/501 (#20)
Co-authored-by: Rodactor <rodactor@roblox.com>
2021-11-03 10:15:50 -07:00

131 lines
4.2 KiB
Lua

local bench = script and require(script.Parent.bench_support) or require("bench_support")
function test()
--The Computer Language Benchmarks Game
-- https://salsa.debian.org/benchmarksgame-team/benchmarksgame/
--contributed by Mike Pall
local PI = 3.141592653589793
local SOLAR_MASS = 4 * PI * PI
local DAYS_PER_YEAR = 365.24
local bodies = {
{ --Sun
x = 0,
y = 0,
z = 0,
vx = 0,
vy = 0,
vz = 0,
mass = SOLAR_MASS
},
{ --Jupiter
x = 4.84143144246472090e+00,
y = -1.16032004402742839e+00,
z = -1.03622044471123109e-01,
vx = 1.66007664274403694e-03 * DAYS_PER_YEAR,
vy = 7.69901118419740425e-03 * DAYS_PER_YEAR,
vz = -6.90460016972063023e-05 * DAYS_PER_YEAR,
mass = 9.54791938424326609e-04 * SOLAR_MASS
},
{ --Saturn
x = 8.34336671824457987e+00,
y = 4.12479856412430479e+00,
z = -4.03523417114321381e-01,
vx = -2.76742510726862411e-03 * DAYS_PER_YEAR,
vy = 4.99852801234917238e-03 * DAYS_PER_YEAR,
vz = 2.30417297573763929e-05 * DAYS_PER_YEAR,
mass = 2.85885980666130812e-04 * SOLAR_MASS
},
{ --Uranus
x = 1.28943695621391310e+01,
y = -1.51111514016986312e+01,
z = -2.23307578892655734e-01,
vx = 2.96460137564761618e-03 * DAYS_PER_YEAR,
vy = 2.37847173959480950e-03 * DAYS_PER_YEAR,
vz = -2.96589568540237556e-05 * DAYS_PER_YEAR,
mass = 4.36624404335156298e-05 * SOLAR_MASS
},
{ --Neptune
x = 1.53796971148509165e+01,
y = -2.59193146099879641e+01,
z = 1.79258772950371181e-01,
vx = 2.68067772490389322e-03 * DAYS_PER_YEAR,
vy = 1.62824170038242295e-03 * DAYS_PER_YEAR,
vz = -9.51592254519715870e-05 * DAYS_PER_YEAR,
mass = 5.15138902046611451e-05 * SOLAR_MASS
}
}
local function advance(bodies, nbody, dt)
for i = 1, nbody do
local bi = bodies[i]
local bix, biy, biz, bimass = bi.x, bi.y, bi.z, bi.mass
local bivx, bivy, bivz = bi.vx, bi.vy, bi.vz
for j = i + 1, nbody do
local bj = bodies[j]
local dx, dy, dz = bix - bj.x, biy - bj.y, biz - bj.z
local distance = math.sqrt(dx*dx + dy*dy + dz*dz)
local mag = dt / (distance * distance * distance)
local bim, bjm = bimass*mag, bj.mass*mag
bivx = bivx - (dx * bjm)
bivy = bivy - (dy * bjm)
bivz = bivz - (dz * bjm)
bj.vx = bj.vx + (dx * bim)
bj.vy = bj.vy + (dy * bim)
bj.vz = bj.vz + (dz * bim)
end
bi.vx = bivx
bi.vy = bivy
bi.vz = bivz
end
for i = 1, nbody do
local bi = bodies[i]
bi.x = bi.x + (dt * bi.vx)
bi.y = bi.y + (dt * bi.vy)
bi.z = bi.z + (dt * bi.vz)
end
end
local function energy(bodies, nbody)
local e = 0
for i = 1, nbody do
local bi = bodies[i]
local vx, vy, vz, bim = bi.vx, bi.vy, bi.vz, bi.mass
e = e + (0.5 * bim * (vx*vx + vy*vy + vz*vz))
for j = i + 1, nbody do
local bj = bodies[j]
local dx, dy, dz = bi.x - bj.x, bi.y - bj.y, bi.z - bj.z
local distance = math.sqrt(dx*dx + dy*dy + dz*dz)
e = e - ((bim * bj.mass) / distance)
end
end
return e
end
local function offsetMomentum(b, nbody)
local px, py, pz = 0, 0, 0
for i = 1, nbody do
local bi = b[i]
local bim = bi.mass
px = px + (bi.vx * bim)
py = py + (bi.vy * bim)
pz = pz + (bi.vz * bim)
end
b[1].vx = -px / SOLAR_MASS
b[1].vy = -py / SOLAR_MASS
b[1].vz = -pz / SOLAR_MASS
end
local N = 20000
local nbody = #bodies
local ts0 = os.clock()
offsetMomentum(bodies, nbody)
for i = 1, N do advance(bodies, nbody, 0.01) end
local ts1 = os.clock()
return ts1 - ts0
end
bench.runCode(test, "n-body")