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#!/usr/bin/env python3
#
# --- Input file to test the particle scraper and the Python wrappers
# --- to access the buffer of scraped particles.
import pywarpx
from pywarpx import picmi
##########################
# numerics parameters
##########################
# --- Number of time steps
max_steps = 60
diagnostic_intervals = 20
# --- Grid
nx = 64
ny = 64
nz = 128
cfl = 0.99
xmin = -125e-6
ymin = -125e-6
zmin = -149e-6
xmax = 125e-6
ymax = 125e-6
zmax = 1e-6
##########################
# physics components
##########################
uniform_plasma_elec = picmi.UniformDistribution(
density = 1e23, # number of electrons per m^3
lower_bound = [-1e-5, -1e-5, -149e-6],
upper_bound = [1e-5, 1e-5, -129e-6],
directed_velocity = [0., 0., 2000.*picmi.constants.c] # uth the std of the (unitless) momentum
)
electrons = picmi.Species(
particle_type='electron', name='electrons',
initial_distribution=uniform_plasma_elec,
warpx_save_particles_at_xhi=1, warpx_save_particles_at_eb=1
)
##########################
# numerics components
##########################
grid = picmi.Cartesian3DGrid(
number_of_cells = [nx, ny, nz],
lower_bound = [xmin, ymin, zmin],
upper_bound = [xmax, ymax, zmax],
lower_boundary_conditions=['none', 'none', 'none'],
upper_boundary_conditions=['none', 'none', 'none'],
lower_boundary_conditions_particles=['open', 'open', 'open'],
upper_boundary_conditions_particles=['open', 'open', 'open'],
warpx_max_grid_size = 32
)
solver = picmi.ElectromagneticSolver(
grid=grid, cfl=cfl
)
embedded_boundary = picmi.EmbeddedBoundary(
implicit_function="-max(max(max(x-12.5e-6,-12.5e-6-x),max(y-12.5e-6,-12.5e-6-y)),max(z-(-6.15e-5),-8.65e-5-z))"
)
##########################
# diagnostics
##########################
field_diag = picmi.FieldDiagnostic(
name = 'diag1',
grid = grid,
period = diagnostic_intervals,
data_list = ['Ex', 'Ey', 'Ez', 'Bx', 'By', 'Bz'],
write_dir = '.',
warpx_file_prefix = 'Python_particle_scrape_plt'
)
##########################
# simulation setup
##########################
sim = picmi.Simulation(
solver = solver,
max_steps = max_steps,
warpx_embedded_boundary=embedded_boundary,
verbose=True,
warpx_load_balance_intervals=40,
warpx_load_balance_efficiency_ratio_threshold=0.9
)
sim.add_species(
electrons,
layout = picmi.GriddedLayout(
n_macroparticle_per_cell=[1, 1, 1], grid=grid
)
)
sim.add_diagnostic(field_diag)
##########################
# simulation run
##########################
# sim.write_input_file(file_name = 'inputs_from_PICMI')
sim.step(max_steps)
################################################
# check that the wrappers to access the particle
# buffer functions as intended
################################################
from mpi4py import MPI as mpi
my_id = pywarpx.getMyProc()
n = pywarpx.get_particle_boundary_buffer_size("electrons", 'eb')
print(f"Number of electrons in buffer (proc #{my_id}): {n}")
assert n == 612
scraped_steps = pywarpx.get_particle_boundary_buffer("electrons", 'eb', 'step_scraped', 0)
for arr in scraped_steps:
assert all(arr > 40)
weights = pywarpx.get_particle_boundary_buffer("electrons", 'eb', 'w', 0)
n = sum(len(arr) for arr in weights)
print(f"Number of electrons in this proc's buffer (proc #{my_id}): {n}")
n_sum = mpi.COMM_WORLD.allreduce(n, op=mpi.SUM)
assert n_sum == 612
# clear the particle buffer
pywarpx.clearParticleBoundaryBuffer()
# confirm that the buffer was cleared
n = pywarpx.get_particle_boundary_buffer_size("electrons", 'eb')
print(f"Number of electrons in buffer (proc #{my_id}): {n}")
assert n == 0
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