def test_waveforms_all_bends(backends):
fdtd.set_backend(backends)
times = np.arange(0,1000) / 1000.0
waveform_array = normalized_gaussian_pulse(times, 0.01,center =0.5)
assert np.max(waveform_array) == pytest.approx(1.0, rel=0.1)
assert waveform_array[0] == pytest.approx(0.0, rel=1e-6)
assert waveform_array[-1] == pytest.approx(0.0, rel=1e-6)
def test_DC_absorbing_current_detector_all_bends(grid, pml, backends):
fdtd.set_backend(backends)
# we maybe want our test cases to be orthogonal:
# The test case with the patch antenna also relies on other modules like
# the electric field detector & PEC, seems like a smaller test could be in order
# However, because of the overlapping object issue, seems like this'll be harder.
# This doesn't seem to work properly, not sure why-
# see issue #11, will look into it.
conductivity = 1e9
# absorb = bd.ones((grid.Nx,grid.Ny,grid.Nz))
# absorb[x_,y_,z_] = 0
grid[x_ - 1 : x_ + 1, y_ - 1 : y_ + 1, z_ - 1 : z_ + 1] = fdtd.AbsorbingObject(
permittivity=1.0, conductivity=conductivity
)
# AbsorbingObject doesn't create a magnetic field?
# How could that ever cause a current density?
# grid[x_,y_,z_] = fdtd.PointSource(period=500)
cd = fdtd.CurrentDetector(name="Dave")
grid[x_, y_, z_] = cd
grid[x_:x_, y_:y_, z_:z_] = fdtd.BlockDetector()
# FIXME: AbsorbingObject must be added last for some reason,
n = 1000
# grid.run(total_time=n)
for _ in range(n):
grid.update_E()
grid.E[x_, y_, z_, Z] = normalized_gaussian_pulse(
grid.time_passed,
(n / 10.0) * grid.time_step,
center=(n / 2) * grid.time_step,
)
grid.update_H()
grid.time_steps_passed += 1
#
current_time_history = bd.array(grid.detectors[0].I).reshape(n)
electric_field_time_history = bd.array(grid.detectors[1].E).reshape(n, 3)[:, Z]
# print(grid.E[x_,y_,z_,Z])
#
# print(current_time_history)
voltage = electric_field_time_history * grid.grid_spacing
resistivity = 1.0 / conductivity
resistance = (resistivity * grid.grid_spacing) / (
grid.grid_spacing * grid.grid_spacing
)
expected_current = voltage / resistance
def test_antenna_impedance():
fdtd.set_backend("torch.cuda.float32")
# a very slow test
distance_from_edge = bd.array([0.0,0.25,0.35,0.50,0.67,1.00])
samaras_FDTD_R = bd.array([169,136,106,72,32,0])
grid, source, simulation_steps = create_patch_antenna(0)
for idx, d in enumerate(distance_from_edge):
grid, source, _ = create_patch_antenna(d)
grid.run(simulation_steps)
fr = FrequencyRoutines(grid, source)
fr.impedance()
A simple example on how to use the FDTD Library
"""
## Imports
import matplotlib.pyplot as plt
import fdtd
import fdtd.backend as bd
## Set Backend
fdtd.set_backend("numpy")
## Constants
WAVELENGTH = 1550e-9
SPEED_LIGHT: float = 299_792_458.0 # [m/s] speed of light
## Simulation
# create FDTD Grid
grid = fdtd.Grid(
(2.5e-5, 1.5e-5, 1),
grid_spacing=0.1 * WAVELENGTH,
permittivity=1.0,
permeability=1.0,
def test_set_backend():
fdtd.set_backend("torch")
assert isinstance(fdtd.backend, TorchBackend)
fdtd.set_backend("numpy")
assert isinstance(fdtd.backend, NumpyBackend)
A simple example on how to use the FDTD Library
"""
## Imports
import matplotlib.pyplot as plt
from line_profiler import LineProfiler
import fdtd
import fdtd.backend as bd
## Set Backend
fdtd.set_backend("torch.cuda")
## Constants
WAVELENGTH = 1550e-9
SPEED_LIGHT: float = 299_792_458.0 # [m/s] speed of light
## Simulation
# create FDTD Grid
grid = fdtd.Grid(
(2.5e-5, 1.5e-5, 1),
grid_spacing=0.1 * WAVELENGTH,
permittivity=1.0,
permeability=1.0,
)
