class TestVoronoiMesh2dBox(unittest.TestCase):
def setUp(self):
L = 1. # box size
n = 50 # number of points
self.dx = L / n
# add ghost 3 ghost particles to the sides for the tesselation
# wont suffer from edge boundaries
x = (np.arange(n + 6, dtype=np.float64) - 3) * self.dx + 0.5 * self.dx
# generate the grid of particle positions
X, Y = np.meshgrid(x, x)
Y = np.flipud(Y)
x = X.flatten()
y = Y.flatten()
# find all particles inside the unit box
indices = (((0. <= x) & (x <= 1.)) & ((0. <= y) & (y <= 1.)))
x_in = x[indices]
y_in = y[indices]
self.num_real = x_in.size
self.particles = ParticleContainer(x_in.size)
# store ghost particles
xp = self.particles["position-x"]
yp = self.particles["position-y"]
xp[:] = x_in
yp[:] = y_in
# store ghost particles
x_out = x[~indices]
y_out = y[~indices]
self.num_ghost = x_out.size
self.particles.extend(x_out.size)
tag = self.particles["tag"]
xp = self.particles["position-x"]
yp = self.particles["position-y"]
xp[self.num_real:] = x_out
yp[self.num_real:] = y_out
tag[self.num_real:] = ParticleTAGS.Ghost
# put real particles in front of the arrays
# type = self.particles["tag"]
# type[:] = ParticleTAGS.Ghost
# self.particles.align_particles()
# vol = self.particles["volume"]
# vol[:] = 0.0
def test_volume_2D(self):
"""Test particle volumes in square created correctly.
Create grid of particles in a unit box, total volume
is 1.0. Create tessellation and sum all particle
volumes.
"""
pos = np.array(
[self.particles["position-x"], self.particles["position-y"]])
# generate voronoi mesh
mesh = VoronoiMesh2D()
mesh.tessellate(pos)
# calculate voronoi volumes of all real particles
mesh.compute_cell_info(self.particles)
real_indices = self.particles["tag"] == ParticleTAGS.Real
tot_vol = np.sum(self.particles["volume"][real_indices])
self.assertAlmostEqual(tot_vol, 1.0)
def test_volume_perturb_2D(self):
"""Test particle volumes in a perturb sub-square are created correctly.
Create grid of particles in a unit box, and perturb the positions
in a sub-square. Total volume is 1.0. Create tessellation and sum all
particle volumes.
"""
# find particles in the interior box
x_in = self.particles["position-x"]
y_in = self.particles["position-y"]
k = ((0.25 < x_in) & (x_in < 0.5)) & ((0.25 < y_in) & (y_in < 0.5))
# randomly perturb their positions
num_points = k.sum()
x_in[k] += 0.2 * self.dx * (2.0 * np.random.random(num_points) - 1.0)
y_in[k] += 0.2 * self.dx * (2.0 * np.random.random(num_points) - 1.0)
pos = np.array(
[self.particles["position-x"], self.particles["position-y"]])
# generate voronoi mesh
mesh = VoronoiMesh2D()
mesh.tessellate(pos)
# calculate voronoi volumes of all real particles
mesh.compute_cell_info(self.particles)
real_indices = self.particles["tag"] == ParticleTAGS.Real
tot_vol = np.sum(self.particles["volume"][real_indices])
self.assertAlmostEqual(tot_vol, 1.0)
def test_center_of_mass_2D(self):
"""Test if particle center of mass positions are created correctly.
Particles or in a uniform unit box. So com is just the particle
positions.
"""
pos = np.array(
[self.particles["position-x"], self.particles["position-y"]])
# generate voronoi mesh
mesh = VoronoiMesh2D()
mesh.tessellate(pos)
# calculate voronoi volumes of all real particles
mesh.compute_cell_info(self.particles)
real_indices = self.particles["tag"] == ParticleTAGS.Real
xcom = self.particles["com-x"][real_indices]
ycom = self.particles["com-y"][real_indices]
xp = self.particles["position-x"][real_indices]
yp = self.particles["position-y"][real_indices]
for i in range(xp.size):
self.assertAlmostEqual(xcom[i], xp[i])
self.assertAlmostEqual(ycom[i], yp[i])
class TestVoronoiMesh2dRectangle(unittest.TestCase):
def setUp(self):
xvals = -2 * np.random.random(2) + 1
self.xmin = np.min(xvals)
self.xmax = np.max(xvals)
L = (self.xmax - self.xmin) # size in x
n = 50 # number of points along dimension
self.dx = L / n
# add ghost 3 ghost particles to the sides for the tesselation
# wont suffer from edge boundaries
x = self.xmin + (np.arange(n + 6, dtype=np.float64) -
3) * self.dx + 0.5 * self.dx
yvals = -2 * np.random.random(2) + 1
self.ymin = np.min(yvals)
self.ymax = np.max(yvals)
L = (self.ymax - self.ymin) # size in x
n = 50 # number of points along dimension
self.dy = L / n
# add ghost 3 ghost particles to the sides for the tesselation
# wont suffer from edge boundaries
y = self.ymin + (np.arange(n + 6, dtype=np.float64) -
3) * self.dy + 0.5 * self.dy
# generate the grid of particle positions
X, Y = np.meshgrid(x, y)
Y = np.flipud(Y)
x = X.flatten()
y = Y.flatten()
# find all particles inside the unit box
indices = (((self.xmin <= x) & (x <= self.xmax)) & ((self.ymin <= y) &
(y <= self.ymax)))
x_in = x[indices]
y_in = y[indices]
self.num_real = x_in.size
self.particles = ParticleContainer(x_in.size)
# store ghost particles
xp = self.particles["position-x"]
yp = self.particles["position-y"]
xp[:] = x_in
yp[:] = y_in
# store ghost particles
x_out = x[~indices]
y_out = y[~indices]
self.num_ghost = x_out.size
self.particles.extend(x_out.size)
tag = self.particles["tag"]
xp = self.particles["position-x"]
yp = self.particles["position-y"]
xp[self.num_real:] = x_out
yp[self.num_real:] = y_out
tag[self.num_real:] = ParticleTAGS.Ghost
# put real particles in front of the arrays
# type = self.particles["tag"]
# type[:] = ParticleTAGS.Ghost
# self.particles.align_particles()
# vol = self.particles["volume"]
# vol[:] = 0.0
def test_volume_2D(self):
"""Test particle volumes in random rectangle are created correctly.
Create grid of particles in a random size rectangle. Create
tessellation and sum all particle volumes.
"""
pos = np.array(
[self.particles["position-x"], self.particles["position-y"]])
# generate voronoi mesh
mesh = VoronoiMesh2D()
mesh.tessellate(pos)
# calculate voronoi volumes of all real particles
mesh.compute_cell_info(self.particles)
real_indices = self.particles["tag"] == ParticleTAGS.Real
tot_vol = np.sum(self.particles["volume"][real_indices])
self.assertAlmostEqual(tot_vol, ((self.xmax - self.xmin) *
(self.ymax - self.ymin)))
def test_volume_perturb_2D(self):
"""Test if random particle volumes are created correctly.
First create a grid of particles in a unit box. So
the total volume is 1.0. Then perturb the particles
in a box of unit lenght 0.5. Create the tessellation
and compare the sum of all the particle volumes and
the total volume.
"""
Lx = self.xmax - self.xmin
Ly = self.ymax - self.ymin
xlo = self.xmin + 0.25 * Lx
xhi = self.xmin + 0.75 * Lx
ylo = self.ymin + 0.25 * Ly
yhi = self.ymin + 0.75 * Ly
# find particles in the interior box
x_in = self.particles["position-x"]
y_in = self.particles["position-y"]
k = ((xlo < x_in) & (x_in < xhi)) & ((ylo < y_in) & (y_in < yhi))
# randomly perturb their positions
num_points = k.sum()
x_in[k] += 0.2 * self.dx * (2.0 * np.random.random(num_points) - 1.0)
y_in[k] += 0.2 * self.dy * (2.0 * np.random.random(num_points) - 1.0)
pos = np.array(
[self.particles["position-x"], self.particles["position-y"]])
# generate voronoi mesh
mesh = VoronoiMesh2D()
mesh.tessellate(pos)
# calculate voronoi volumes of all real particles
mesh.compute_cell_info(self.particles)
real_indices = self.particles["tag"] == ParticleTAGS.Real
tot_vol = np.sum(self.particles["volume"][real_indices])
self.assertAlmostEqual(tot_vol, Lx * Ly)
def test_center_of_mass_2D(self):
"""Test if particle center of mass positions are created correctly.
Particles are placed equally spaced in each direction. So com is
just the particle positions.
"""
pos = np.array(
[self.particles["position-x"], self.particles["position-y"]])
# generate voronoi mesh
mesh = VoronoiMesh2D()
mesh.tessellate(pos)
# calculate voronoi volumes of all real particles
mesh.compute_cell_info(self.particles)
real_indices = self.particles["tag"] == ParticleTAGS.Real
xcom = self.particles["com-x"][real_indices]
ycom = self.particles["com-y"][real_indices]
xp = self.particles["position-x"][real_indices]
yp = self.particles["position-y"][real_indices]
for i in range(xp.size):
self.assertAlmostEqual(xcom[i], xp[i])
self.assertAlmostEqual(ycom[i], yp[i])