def __init__(self, owner: Simulation, input_data: dict):
super().__init__(owner, input_data)
self.position = np.zeros((1, 3))
self.momentum = np.zeros((1, 3))
self.mass = input_data.get('mass', 1)
self.spring_constant = input_data.get('spring_constant', 1)
self.push = owner.find_tool_by_name(input_data["pusher"]).push
def simulation_fixture():
"""Creates a simulation object used to create a B.O.S. object"""
input_data = {
"Tools": {
"ForwardEuler": {}
},
"Clock": {
"start_time": 0,
"end_time": 1,
"dt": 1
},
"PhysicsModules": {},
"Diagnostics": {},
}
simulation = Simulation(input_data)
simulation.prepare_simulation()
return simulation
def test_bos_leapfrog(bos_run, tmp_path):
"""Tests block_on_spring app with LeapFrog ComputeTool and compares to
output files with a "good" output.
"""
bos_run["PhysicsModules"]["BlockOnSpring"]["pusher"] = "Leapfrog"
bos_run["Diagnostics"]["directory"] = tmp_path / "output"
sim = Simulation(bos_run)
sim.run()
for filename in ['block_p', 'block_x', 'time']:
ref_data = np.genfromtxt(
f'tests/fixtures/block_on_spring/output_leapfrog/{filename}.csv',
delimiter=',')
tmp_data = np.genfromtxt(tmp_path / f'output/{filename}.csv',
delimiter=',')
assert np.allclose(ref_data, tmp_data, rtol=1e-05, atol=1e-08)
def test_bos_leapfrog(bos_config):
"""Tests block_on_spring app with LeapFrog ComputeTool and compares to
output files with a "good" output.
"""
bos_config["PhysicsModules"]["BlockOnSpring"]["pusher"] = "Leapfrog"
bos_config["Diagnostics"]["directory"] = ("test_data/test_output/"
"output_Leapfrog/")
sim = Simulation(bos_config)
sim.run()
for filename in ['block_p', 'block_x', 'time']:
ref_data = np.genfromtxt(
'test_data/reference_output/'
f'output_Leapfrog/{filename}.csv',
delimiter=',')
tmp_data = np.genfromtxt(
'test_data/test_output/'
f'output_Leapfrog/{filename}.csv',
delimiter=',')
assert np.allclose(ref_data, tmp_data)
def __init__(self, owner: Simulation, input_data: dict):
super().__init__(owner, input_data)
self.E = None
self.x = input_data["position"]
self.interp_field = owner.grid.create_interpolator(self.x)
self.position = np.zeros((1, 3))
self.momentum = np.zeros((1, 3))
self.eoverm = 1.7588e11
self.charge = 1.6022e-19
self.mass = 9.1094e-31
self.push = owner.find_tool_by_name(input_data["pusher"]).push
def bos_run():
# Note: grid isn't used, but "gridless" sims aren't an option yet
problem_config = {
"Grid": {"N": 2, "x_min": 0, "x_max": 1},
"Clock": {"start_time": 0,
"end_time": 10,
"num_steps": 10},
"PhysicsModules": {
"BlockOnSpring": {
"mass": 1,
"spring_constant": 1,
"pusher": "Leapfrog",
"x0": [0, 1, 0],
"p0": [0, 0, 0]
}
},
"Tools": {
"Leapfrog": {},
"BlockForwardEuler": {},
"BackwardEuler": {}
},
"Diagnostics": {
# default values come first
"directory": "tmp/block_on_spring/output_leapfrog/",
"output_type": "csv",
"clock": {"filename": "time.csv"},
"BlockDiagnostic": [
{'component': 'momentum', 'filename': 'block_p.csv'},
{'component': 'position', 'filename': 'block_x.csv'}
]
}
}
sim = Simulation(problem_config)
sim.run()
problem_config["PhysicsModules"]["BlockOnSpring"]["pusher"] = "BlockForwardEuler"
problem_config["Diagnostics"]["directory"] = "tmp/block_on_spring/output_forwardeuler/"
sim = Simulation(problem_config)
sim.run()
problem_config["PhysicsModules"]["BlockOnSpring"]["pusher"] = "BackwardEuler"
problem_config["Diagnostics"]["directory"] = "tmp/block_on_spring/output_backwardeuler/"
sim = Simulation(problem_config)
sim.run()
'units': 'kg m/s',
'coords': ["dim0", "vector component"],
'long_name': 'Block Momentum'
},
{
'name': 'Block:position',
'units': 'm',
'coords': ["dim0", "vector component"],
'long_name': 'Block Position'
},
]
}
}
}
sim = Simulation(block_config)
sim.run()
block_config["PhysicsModules"]["BlockOnSpring"]["pusher"] = "ForwardEuler"
block_config["Diagnostics"]["directory"] = "output_euler/"
sim = Simulation(block_config)
sim.run()
# Now plot the outputs
lf_output = xr.load_dataset('output_leapfrog/output.nc')
print(lf_output)
lf_output['Block:position'][:, 1].plot(x='time', label='Leapfrog')
plt.show()
fe_output = xr.load_dataset('output_euler/output.nc')
"Leapfrog": {},
"ForwardEuler": {},
},
"Diagnostics": {
# default values come first
"directory":
"output_leapfrog/",
"output_type":
"csv",
"clock": {
"filename": "time.csv"
},
"BlockDiagnostic": [{
'component': 'momentum',
'filename': 'block_p.csv'
}, {
'component': 'position',
'filename': 'block_x.csv'
}]
}
}
sim = Simulation(problem_config)
sim.run()
problem_config["PhysicsModules"]["BlockOnSpring"]["pusher"] = "ForwardEuler"
problem_config["Diagnostics"]["directory"] = "output_euler/"
sim = Simulation(problem_config)
sim.run()
def print_diagnose(self, data):
print(data)
def csv_diagnose(self, data):
self.csv.append(data)
class ForwardEuler(ComputeTool):
def __init__(self, owner: Simulation, input_data: dict):
super().__init__(owner, input_data)
self.dt = None
def initialize(self):
self.dt = self.owner.clock.dt
def push(self, position, momentum, charge, mass, E, B):
p0 = momentum.copy()
momentum[:] = momentum + self.dt * E * charge
position[:] = position + self.dt * p0 / mass
PhysicsModule.register("EMWave", EMWave)
PhysicsModule.register("ChargedParticle", ChargedParticle)
Diagnostic.register("ParticleDiagnostic", ParticleDiagnostic)
ComputeTool.register("ForwardEuler", ForwardEuler)
input_file = "particle_in_field.toml"
sim = Simulation(input_file)
sim.run()