def test_sqrt(self):
@function(Double, x=Double)
def sqrt(x):
return nitrous.lib.math.sqrt(Double)(x)
m = module([sqrt])
self.assertAlmostEqual(math.sqrt(10.0), m.sqrt(10.0))
def energy(xyz, vxyz, mass, n_bodies):
e = 0.0
for i in range(n_bodies):
vx = vxyz[i, X]
vy = vxyz[i, Y]
vz = vxyz[i, Z]
e += 0.5 * mass[i] * (vx * vx + vy * vy + vz * vz)
for j in range(i + 1, n_bodies):
dx = xyz[i, X] - xyz[j, X]
dy = xyz[i, Y] - xyz[j, Y]
dz = xyz[i, Z] - xyz[j, Z]
d2 = dx * dx + dy * dy + dz * dz
e -= mass[i] * mass[j] / sqrt(Double)(d2)
return e
def energy(xyz, vxyz, mass, n_bodies):
e = 0.0
for i in range(n_bodies):
vx = vxyz[i, X]
vy = vxyz[i, Y]
vz = vxyz[i, Z]
e += 0.5 * mass[i] * (vx * vx + vy * vy + vz * vz)
for j in range(i + 1, n_bodies):
dx = xyz[i, X] - xyz[j, X]
dy = xyz[i, Y] - xyz[j, Y]
dz = xyz[i, Z] - xyz[j, Z]
d2 = dx * dx + dy * dy + dz * dz
e -= mass[i] * mass[j] / sqrt(Double)(d2)
return e
def advance(xyz, vxyz, mass, n_bodies, dt):
for i in range(n_bodies):
for j in range(i + 1, n_bodies):
dx = xyz[i, X] - xyz[j, X]
dy = xyz[i, Y] - xyz[j, Y]
dz = xyz[i, Z] - xyz[j, Z]
d2 = dx * dx + dy * dy + dz * dz
mag = dt / (d2 * sqrt(Double)(d2))
vxyz[i, X] -= dx * mass[j] * mag
vxyz[i, Y] -= dy * mass[j] * mag
vxyz[i, Z] -= dz * mass[j] * mag
vxyz[j, X] += dx * mass[i] * mag
vxyz[j, Y] += dy * mass[i] * mag
vxyz[j, Z] += dz * mass[i] * mag
for i in range(n_bodies):
xyz[i, X] += dt * vxyz[i, X]
xyz[i, Y] += dt * vxyz[i, Y]
xyz[i, Z] += dt * vxyz[i, Z]
def advance(xyz, vxyz, mass, n_bodies, dt):
for i in range(n_bodies):
for j in range(i + 1, n_bodies):
dx = xyz[i, X] - xyz[j, X]
dy = xyz[i, Y] - xyz[j, Y]
dz = xyz[i, Z] - xyz[j, Z]
d2 = dx * dx + dy * dy + dz * dz
mag = dt / (d2 * sqrt(Double)(d2))
vxyz[i, X] -= dx * mass[j] * mag
vxyz[i, Y] -= dy * mass[j] * mag
vxyz[i, Z] -= dz * mass[j] * mag
vxyz[j, X] += dx * mass[i] * mag
vxyz[j, Y] += dy * mass[i] * mag
vxyz[j, Z] += dz * mass[i] * mag
for i in range(n_bodies):
xyz[i, X] += dt * vxyz[i, X]
xyz[i, Y] += dt * vxyz[i, Y]
xyz[i, Z] += dt * vxyz[i, Z]
def _norm(a):
return sqrt(Double)(a.x * a.x + a.y * a.y + a.z * a.z)
def _norm(a):
return sqrt(Double)(a.x * a.x + a.y * a.y + a.z * a.z)
