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author | Jari Vetoniemi <jari.vetoniemi@indooratlas.com> | 2020-03-16 18:49:26 +0900 |
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committer | Jari Vetoniemi <jari.vetoniemi@indooratlas.com> | 2020-03-30 00:39:06 +0900 |
commit | fcbf63e62c627deae76c1b8cb8c0876c536ed811 (patch) | |
tree | 64cb17de3f41a2b6fef2368028fbd00349946994 /jni/ruby/benchmark/bm_so_nbody.rb |
Fresh start
Diffstat (limited to 'jni/ruby/benchmark/bm_so_nbody.rb')
-rw-r--r-- | jni/ruby/benchmark/bm_so_nbody.rb | 148 |
1 files changed, 148 insertions, 0 deletions
diff --git a/jni/ruby/benchmark/bm_so_nbody.rb b/jni/ruby/benchmark/bm_so_nbody.rb new file mode 100644 index 0000000..d6c5bb9 --- /dev/null +++ b/jni/ruby/benchmark/bm_so_nbody.rb @@ -0,0 +1,148 @@ +# The Computer Language Shootout +# http://shootout.alioth.debian.org +# +# Optimized for Ruby by Jesse Millikan +# From version ported by Michael Neumann from the C gcc version, +# which was written by Christoph Bauer. + +SOLAR_MASS = 4 * Math::PI**2 +DAYS_PER_YEAR = 365.24 + +def _puts *args +end + +class Planet + attr_accessor :x, :y, :z, :vx, :vy, :vz, :mass + + def initialize(x, y, z, vx, vy, vz, mass) + @x, @y, @z = x, y, z + @vx, @vy, @vz = vx * DAYS_PER_YEAR, vy * DAYS_PER_YEAR, vz * DAYS_PER_YEAR + @mass = mass * SOLAR_MASS + end + + def move_from_i(bodies, nbodies, dt, i) + while i < nbodies + b2 = bodies[i] + dx = @x - b2.x + dy = @y - b2.y + dz = @z - b2.z + + distance = Math.sqrt(dx * dx + dy * dy + dz * dz) + mag = dt / (distance * distance * distance) + b_mass_mag, b2_mass_mag = @mass * mag, b2.mass * mag + + @vx -= dx * b2_mass_mag + @vy -= dy * b2_mass_mag + @vz -= dz * b2_mass_mag + b2.vx += dx * b_mass_mag + b2.vy += dy * b_mass_mag + b2.vz += dz * b_mass_mag + i += 1 + end + + @x += dt * @vx + @y += dt * @vy + @z += dt * @vz + end +end + +def energy(bodies) + e = 0.0 + nbodies = bodies.size + + for i in 0 ... nbodies + b = bodies[i] + e += 0.5 * b.mass * (b.vx * b.vx + b.vy * b.vy + b.vz * b.vz) + for j in (i + 1) ... nbodies + b2 = bodies[j] + dx = b.x - b2.x + dy = b.y - b2.y + dz = b.z - b2.z + distance = Math.sqrt(dx * dx + dy * dy + dz * dz) + e -= (b.mass * b2.mass) / distance + end + end + e +end + +def offset_momentum(bodies) + px, py, pz = 0.0, 0.0, 0.0 + + for b in bodies + m = b.mass + px += b.vx * m + py += b.vy * m + pz += b.vz * m + end + + b = bodies[0] + b.vx = - px / SOLAR_MASS + b.vy = - py / SOLAR_MASS + b.vz = - pz / SOLAR_MASS +end + +BODIES = [ + # sun + Planet.new(0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 1.0), + + # jupiter + Planet.new( + 4.84143144246472090e+00, + -1.16032004402742839e+00, + -1.03622044471123109e-01, + 1.66007664274403694e-03, + 7.69901118419740425e-03, + -6.90460016972063023e-05, + 9.54791938424326609e-04), + + # saturn + Planet.new( + 8.34336671824457987e+00, + 4.12479856412430479e+00, + -4.03523417114321381e-01, + -2.76742510726862411e-03, + 4.99852801234917238e-03, + 2.30417297573763929e-05, + 2.85885980666130812e-04), + + # uranus + Planet.new( + 1.28943695621391310e+01, + -1.51111514016986312e+01, + -2.23307578892655734e-01, + 2.96460137564761618e-03, + 2.37847173959480950e-03, + -2.96589568540237556e-05, + 4.36624404335156298e-05), + + # neptune + Planet.new( + 1.53796971148509165e+01, + -2.59193146099879641e+01, + 1.79258772950371181e-01, + 2.68067772490389322e-03, + 1.62824170038242295e-03, + -9.51592254519715870e-05, + 5.15138902046611451e-05) +] + +init = 200_000 # ARGV[0] +n = Integer(init) + +offset_momentum(BODIES) + +puts "%.9f" % energy(BODIES) + +nbodies = BODIES.size +dt = 0.01 + +n.times do + i = 0 + while i < nbodies + b = BODIES[i] + b.move_from_i(BODIES, nbodies, dt, i + 1) + i += 1 + end +end + +puts "%.9f" % energy(BODIES) |