forked from Aquila-Consortium/JaxPM_highres
87 lines
3.1 KiB
Python
87 lines
3.1 KiB
Python
import jax
|
|
import pytest
|
|
from diffrax import (BacksolveAdjoint, Dopri5, ODETerm, PIDController,
|
|
RecursiveCheckpointAdjoint, SaveAt, diffeqsolve)
|
|
from helpers import MSE
|
|
from jax import numpy as jnp
|
|
|
|
from jaxpm.distributed import uniform_particles
|
|
from jaxpm.painting import cic_paint, cic_paint_dx
|
|
from jaxpm.pm import lpt, make_diffrax_ode
|
|
|
|
|
|
@pytest.mark.single_device
|
|
@pytest.mark.parametrize("order", [1, 2])
|
|
@pytest.mark.parametrize("absolute_painting", [True, False])
|
|
@pytest.mark.parametrize("adjoint", ['DTO', 'OTD'])
|
|
def test_nbody_grad(simulation_config, initial_conditions, lpt_scale_factor,
|
|
nbody_from_lpt1, nbody_from_lpt2, cosmo, order,
|
|
absolute_painting, adjoint):
|
|
|
|
mesh_shape, _ = simulation_config
|
|
cosmo._workspace = {}
|
|
|
|
if adjoint == 'OTD':
|
|
pytest.skip("OTD adjoint not implemented yet (needs PFFT3D JVP)")
|
|
|
|
adjoint = RecursiveCheckpointAdjoint(
|
|
) if adjoint == 'DTO' else BacksolveAdjoint(solver=Dopri5())
|
|
|
|
@jax.jit
|
|
@jax.grad
|
|
def forward_model(initial_conditions, cosmo):
|
|
|
|
# Initial displacement
|
|
if absolute_painting:
|
|
particles = uniform_particles(mesh_shape)
|
|
dx, p, _ = lpt(cosmo,
|
|
initial_conditions,
|
|
particles,
|
|
a=lpt_scale_factor,
|
|
order=order)
|
|
ode_fn = ODETerm(make_diffrax_ode(cosmo, mesh_shape))
|
|
y0 = jnp.stack([particles + dx, p])
|
|
|
|
else:
|
|
dx, p, _ = lpt(cosmo,
|
|
initial_conditions,
|
|
a=lpt_scale_factor,
|
|
order=order)
|
|
ode_fn = ODETerm(
|
|
make_diffrax_ode(cosmo, mesh_shape, paint_absolute_pos=False))
|
|
y0 = jnp.stack([dx, p])
|
|
|
|
solver = Dopri5()
|
|
controller = PIDController(rtol=1e-7,
|
|
atol=1e-7,
|
|
pcoeff=0.4,
|
|
icoeff=1,
|
|
dcoeff=0)
|
|
|
|
saveat = SaveAt(t1=True)
|
|
|
|
solutions = diffeqsolve(ode_fn,
|
|
solver,
|
|
t0=lpt_scale_factor,
|
|
t1=1.0,
|
|
dt0=None,
|
|
y0=y0,
|
|
adjoint=adjoint,
|
|
stepsize_controller=controller,
|
|
saveat=saveat)
|
|
|
|
if absolute_painting:
|
|
final_field = cic_paint(jnp.zeros(mesh_shape), solutions.ys[-1, 0])
|
|
else:
|
|
final_field = cic_paint_dx(solutions.ys[-1, 0])
|
|
|
|
return MSE(final_field,
|
|
nbody_from_lpt1 if order == 1 else nbody_from_lpt2)
|
|
|
|
bad_initial_conditions = initial_conditions + jax.random.normal(
|
|
jax.random.PRNGKey(0), initial_conditions.shape) * 0.5
|
|
best_ic = forward_model(initial_conditions, cosmo)
|
|
bad_ic = forward_model(bad_initial_conditions, cosmo)
|
|
|
|
assert jnp.max(best_ic) < 1e-5
|
|
assert jnp.max(bad_ic) > 1e-5
|