def test_init():
grid = _test_grid("electrostatic_gaussian_sphere", num=50)
# Cartesian
source = (0 * u.mm, -10 * u.mm, 0 * u.mm)
detector = (0 * u.mm, 200 * u.mm, 0 * u.mm)
sim = cpr.Tracker(grid, source, detector, verbose=False)
# Test manually setting hdir and vdir
hdir = np.array([1, 0, 1])
sim = cpr.Tracker(grid,
source,
detector,
verbose=False,
detector_hdir=hdir)
# Test special case hdir == [0,0,1]
source = (0 * u.mm, 0 * u.mm, -10 * u.mm)
detector = (0 * u.mm, 0 * u.mm, 200 * u.mm)
sim = cpr.Tracker(grid, source, detector, verbose=False)
assert all(sim.det_hdir == np.array([1, 0, 0]))
# Test that hdir is calculated correctly if src-det axis is anti-parallel to z
source = (0 * u.mm, 0 * u.mm, 10 * u.mm)
detector = (0 * u.mm, 0 * u.mm, -200 * u.mm)
sim = cpr.Tracker(grid, source, detector, verbose=False)
assert all(sim.det_hdir == np.array([1, 0, 0]))
def test_coordinate_systems():
"""
Check that specifying the same point in different coordinate systems
ends up with identical source and detector vectors.
"""
grid = _test_grid("empty")
# Cartesian
source = (-7.07 * u.mm, -7.07 * u.mm, 0 * u.mm)
detector = (70.07 * u.mm, 70.07 * u.mm, 0 * u.mm)
sim1 = cpr.Tracker(grid, source, detector, verbose=True)
# Cylindrical
source = (-1 * u.cm, 45 * u.deg, 0 * u.mm)
detector = (10 * u.cm, 45 * u.deg, 0 * u.mm)
sim2 = cpr.Tracker(grid, source, detector, verbose=False)
# In spherical
source = (-0.01 * u.m, 90 * u.deg, 45 * u.deg)
detector = (0.1 * u.m, 90 * u.deg, 45 * u.deg)
sim3 = cpr.Tracker(grid, source, detector, verbose=False)
assert np.allclose(sim1.source, sim2.source, atol=1e-2)
assert np.allclose(sim2.source, sim3.source, atol=1e-2)
assert np.allclose(sim1.detector, sim2.detector, atol=1e-2)
assert np.allclose(sim2.detector, sim3.detector, atol=1e-2)
def test_run_options():
grid = _test_grid("electrostatic_gaussian_sphere", num=50)
# Cartesian
source = (0 * u.mm, -10 * u.mm, 0 * u.mm)
detector = (0 * u.mm, 200 * u.mm, 0 * u.mm)
sim = cpr.Tracker(grid, source, detector, verbose=True)
# Test that trying to call run() without creating particles
# raises an exception
with pytest.raises(ValueError):
sim.run()
sim = cpr.Tracker(grid, source, detector, verbose=True)
sim.create_particles(1e4, 3 * u.MeV, max_theta=10 * u.deg)
# Try running with nearest neighbor interpolator
# Test manually setting a timestep
sim.run(field_weighting="nearest neighbor", dt=1e-12 * u.s)
# Test max_deflections
sim.max_deflection
# Test way too big of a max_theta
sim = cpr.Tracker(grid, source, detector, verbose=True)
sim.create_particles(1e4, 3 * u.MeV, max_theta=89 * u.deg)
with pytest.warns(RuntimeWarning,
match="of "
"particles entered the field grid"):
sim.run(field_weighting="nearest neighbor", dt=1e-12 * u.s)
# Test extreme deflections -> warns user
# This requires instantiating a whole new example field with a really
# big B-field
grid = _test_grid("constant_bz", num=50, B0=250 * u.T)
source = (0 * u.mm, -10 * u.mm, 0 * u.mm)
detector = (0 * u.mm, 200 * u.mm, 0 * u.mm)
# Expect warnings because these fields aren't well-behaved at the edges
with pytest.warns(
RuntimeWarning,
match="Fields should go to zero at edges of grid to avoid "):
sim = cpr.Tracker(grid, source, detector, verbose=False)
sim.create_particles(1e4, 3 * u.MeV, max_theta=0.1 * u.deg)
with pytest.warns(
RuntimeWarning,
match="particles have been "
"deflected away from the detector plane",
):
sim.run(field_weighting="nearest neighbor", dt=1e-12 * u.s)
# Calc max deflection: should be between 0 and pi/2
# Note: that's only true because max_theta is very small
# More generally, max_deflection can be a bit bigger than pi/2 for
# particles that begin at an angle then deflect all the way around.
assert 0 < sim.max_deflection.to(u.rad).value < np.pi / 2
def test_load_particles():
grid = _test_grid("electrostatic_gaussian_sphere", num=50)
# Cartesian
source = (0 * u.mm, -10 * u.mm, 0 * u.mm)
detector = (0 * u.mm, 200 * u.mm, 0 * u.mm)
sim = cpr.Tracker(grid, source, detector, verbose=False)
sim.create_particles(1e3,
15 * u.MeV,
max_theta=0.1 * u.rad,
distribution="uniform")
# Test adding unequal numbers of particles
x = np.zeros([100, 3]) * u.m
v = np.ones([150, 3]) * u.m / u.s
with pytest.raises(ValueError):
sim.load_particles(x, v)
# Test creating particles with explicit keywords
x = sim.x * u.m
v = sim.v * u.m / u.s
# Try setting particles going the wrong direction
with pytest.warns(RuntimeWarning):
sim.load_particles(x, -v)
# Try specifying a larger ion (not a proton or electron)
sim.load_particles(x, v, particle="C-12 +3")
# Run the tracker to make sure everything works
sim.run(field_weighting="nearest neighbor")
def run_1D_example(name):
"""
Run a simulation through an example with parameters optimized to
sum up to a lineout along x. The goal is to run a relatively fast
sim with a quasi-1D field grid that can then be summed to get good
enough statistics to use as a test.
"""
grid = _test_grid(name, L=1 * u.mm, num=50)
# Cartesian
source = (0 * u.mm, -10 * u.mm, 0 * u.mm)
detector = (0 * u.mm, 200 * u.mm, 0 * u.mm)
# Expect warnings because these fields aren't well-behaved at the edges
with pytest.warns(
RuntimeWarning,
match="Fields should go to zero at edges of grid to avoid "):
sim = cpr.Tracker(grid, source, detector, verbose=False)
sim.create_particles(1e4, 3 * u.MeV, max_theta=0.1 * u.deg)
sim.run()
size = np.array([[-1, 1], [-1, 1]]) * 10 * u.cm
bins = [200, 60]
hax, vax, values = cpr.synthetic_radiograph(sim, size=size, bins=bins)
values = np.mean(values[:, 20:40], axis=1)
return hax, values
def create_tracker_obj():
# CREATE A RADIOGRAPH OBJECT
grid = _test_grid("electrostatic_gaussian_sphere", num=50)
source = (0 * u.mm, -10 * u.mm, 0 * u.mm)
detector = (0 * u.mm, 200 * u.mm, 0 * u.mm)
sim = cpr.Tracker(grid, source, detector, verbose=False)
sim.create_particles(int(1e4), 3 * u.MeV, max_theta=10 * u.deg)
return sim
def test_create_particles():
grid = _test_grid("electrostatic_gaussian_sphere", num=50)
# Cartesian
source = (0 * u.mm, -10 * u.mm, 0 * u.mm)
detector = (0 * u.mm, 200 * u.mm, 0 * u.mm)
sim = cpr.Tracker(grid, source, detector, verbose=False)
sim.create_particles(
1e3, 15 * u.MeV, max_theta=0.1 * u.rad, distribution="monte-carlo"
)
sim.create_particles(1e3, 15 * u.MeV, max_theta=0.1 * u.rad, distribution="uniform")
# Test specifying particle
charge = 3 * const.e.si
mass = const.m_e.si
sim.create_particles(1e3, 15 * u.MeV, particle="e")
def run_mesh_example(
location=np.array([0, -2, 0]) * u.mm,
extent=(2 * u.mm, 1.5 * u.mm),
nwires=9,
wire_diameter=20 * u.um,
mesh_hdir=None,
mesh_vdir=None,
nparticles=1e4,
problem="electrostatic_gaussian_sphere",
):
"""
Takes all of the add_wire_mesh parameters and runs a standard example problem
simulation using them.
Returns the sim object for use in additional tests
"""
grid = _test_grid(problem, num=100)
source = (0 * u.mm, -10 * u.mm, 0 * u.mm)
detector = (0 * u.mm, 200 * u.mm, 0 * u.mm)
sim = cpr.Tracker(grid, source, detector, verbose=False)
sim.add_wire_mesh(
location,
extent,
nwires,
wire_diameter,
mesh_hdir=mesh_hdir,
mesh_vdir=mesh_vdir,
)
sim.create_particles(nparticles, 3 * u.MeV, max_theta=10 * u.deg)
sim.run(field_weighting="nearest neighbor")
return sim
def test_gaussian_sphere_analytical_comparison():
"""
This test runs a known example problem and compares to a theoretical
model for small deflections.
Still under construction (comparing the actual form of the radiograph
is possible but tricky to implement).
"""
# The Gaussian sphere problem for small deflection potentials
# is solved in Kugland2012relation, and the equations referenced
# below are from that paper.
# https://doi.org/10.1063/1.4750234
a = (1 * u.mm / 3).to(u.mm).value
phi0 = 1.4e5
W = 15e6
l = 10
L = 200
# Define and run the problem
# Setting b to be much larger than the problem so that the field is not
# cut off at the edges. This is required to be directly
# comparable to the theoretical result.
grid = _test_grid(
"electrostatic_gaussian_sphere",
num=100,
phi0=phi0 * u.V,
a=a * u.mm,
b=20 * u.mm,
)
source = (0 * u.mm, -l * u.mm, 0 * u.mm)
detector = (0 * u.mm, L * u.mm, 0 * u.mm)
with pytest.warns(
RuntimeWarning,
match="Fields should go to zero at edges of grid to avoid "):
sim = cpr.Tracker(grid, source, detector, verbose=False)
sim.create_particles(1e3, W * u.eV, max_theta=12 * u.deg)
sim.run()
size = np.array([[-1, 1], [-1, 1]]) * 4 * u.cm
bins = [100, 100]
h, v, i = cpr.synthetic_radiograph(sim, size=size, bins=bins)
h = h.to(u.mm).value / sim.mag
v = v.to(u.mm).value / sim.mag
r0 = h
# Calculate a lineout across the center of the plane (y=0)
v0 = np.argmin(np.abs(v))
line = np.mean(i[:, v0 - 6:v0 + 6], axis=1)
# Zero the edge of the radiograph
line += -np.mean(line)
line *= 1 / np.max(np.abs(line))
# Calculate the theoretical deflection angles (Eq. 28)
theory = phi0 / W * np.sqrt(np.pi) * (r0 / a) * np.exp(-((r0 / a)**2))
max_deflection = np.max(np.abs(theory))
mu = np.sqrt(np.pi) * (phi0 / W) * (l / a)
# sim_mu = sim.max_deflection.to(u.rad).value*(l/a)
# Calculate the theoretical inversion (Eq. 31 )
theory_deflect = -2 * mu * (1 - (r0 / a)**2) * np.exp(-((r0 / a)**2))
theory_deflect *= 1 / np.max(np.abs(theory_deflect))
# Uncomment for debug
"""
print(f"Theory max deflection: {max_deflection:.6f}")
print(f"Theory mu: {mu:.3f}")
print(f"Sim max deflection: {sim.max_deflection.to(u.rad).value:.6f}")
print(f"Sim mu: {sim_mu:.3f}")
import matplotlib.pyplot as plt
print(f"Theory max deflection: {max_deflection:.6f}")
print(f"Theory mu: {mu:.3f}")
print(f"Sim max deflection: {sim.max_deflection.to(u.rad).value:.6f}")
print(f"Sim mu: {sim_mu:.3f}")
fig, ax = plt.subplots()
ax.pcolormesh(h, v, i.T, shading='auto', cmap='Blues_r')
ax.set_aspect('equal')
fig, ax = plt.subplots()
ax.plot(h, line )
ax.plot(h, theory_deflect)
"""
assert np.isclose(max_deflection,
sim.max_deflection.to(u.rad).value,
atol=1e-3)
def test_input_validation():
"""
Intentionally raise a number of errors.
"""
# ************************************************************************
# During initialization
# ************************************************************************
grid = _test_grid("electrostatic_gaussian_sphere")
source = (-10 * u.mm, 90 * u.deg, 45 * u.deg)
detector = (100 * u.mm, 90 * u.deg, 45 * u.deg)
# Check that an error is raised when an input grid has a nan or infty value
# First check NaN
Ex = grid["E_x"]
Ex[0, 0, 0] = np.nan * u.V / u.m
grid.add_quantities(E_x=Ex)
with pytest.raises(ValueError):
sim = cpr.Tracker(grid, source, detector, verbose=False)
Ex[0, 0, 0] = 0 * u.V / u.m
Ex[0, 0, 0] = np.inf * u.V / u.m # Reset element for the rest of the tests
grid.add_quantities(E_x=Ex)
with pytest.raises(ValueError):
sim = cpr.Tracker(grid, source, detector, verbose=False)
Ex[0, 0, 0] = 0 * u.V / u.m
# Check what happens if a value is large relative to the rest of the array
Ex[0, 0, 0] = 0.5 * np.max(Ex)
grid.add_quantities(E_x=Ex)
# with pytest.raises(ValueError):
with pytest.warns(RuntimeWarning):
sim = cpr.Tracker(grid, source, detector, verbose=False)
Ex[0, 0, 0] = 0 * u.V / u.m
# Raise error when source-to-detector vector doesn't pass through the
# field grid
source_bad = (10 * u.mm, -10 * u.mm, 0 * u.mm)
detector_bad = (10 * u.mm, 100 * u.mm, 0 * u.mm)
with pytest.raises(ValueError):
sim = cpr.Tracker(grid, source_bad, detector_bad, verbose=False)
# Test raises warning when one (or more) of the required fields is missing
grid_bad = CartesianGrid(-1 * u.mm, 1 * u.mm, num=50)
with pytest.warns(RuntimeWarning,
match="is not specified for the provided grid."):
sim = cpr.Tracker(grid_bad, source, detector, verbose=True)
# ************************************************************************
# During create_particles
# ************************************************************************
sim = cpr.Tracker(grid, source, detector, verbose=False)
sim.create_particles(1e3, 15 * u.MeV, max_theta=0.99 * np.pi / 2 * u.rad)
# ************************************************************************
# During runtime
# ************************************************************************
sim = cpr.Tracker(grid, source, detector, verbose=False)
sim.create_particles(1e3, 15 * u.MeV)
# Test an invalid field weighting keyword
with pytest.raises(ValueError):
sim.run(field_weighting="not a valid field weighting")
# ************************************************************************
# During runtime
# ************************************************************************
# SYNTHETIC RADIOGRAPH ERRORS
sim.run()
# Choose a very small synthetic radiograph size that misses most of the
# particles
with pytest.warns(
RuntimeWarning,
match="of the particles are shown on this synthetic radiograph."):
size = np.array([[-1, 1], [-1, 1]]) * 1 * u.mm
hax, vax, values = cpr.synthetic_radiograph(sim, size=size)