def test_solve_fastpm_linear_growth():
pm = ParticleMesh(BoxSize=1024.0, Nmesh=(128, 128, 128), dtype='f8')
engine = FastPMEngine(pm)
code = CodeSegment(engine)
code.create_linear_field(whitenoise='whitenoise',
powerspectrum=pk,
dlinear_k='dlinear_k')
code.solve_fastpm(pt=pt,
dlinear_k='dlinear_k',
asteps=[0.1, 0.5, 1.0],
s='s',
v='v',
s1='s1',
s2='s2')
code.get_x(s='s', x='x')
code.paint_simple(x='x', density='density')
field = pm.generate_whitenoise(seed=1234, unitary=True).c2r()
density, dlinear_k, s = code.compute(['density', 'dlinear_k', 's'],
init={'whitenoise': field})
density_k = density.r2c()
p_lin = FFTPower(FieldMesh(dlinear_k), mode='1d')
p_nonlin = FFTPower(FieldMesh(density), mode='1d')
# the simulation shall do a linear growth
t1 = abs((p_nonlin.power['power'] / p_lin.power['power'])**0.5)
assert_allclose(t1[1:4], 1.0, rtol=5e-2)
def test_solve_fastpm():
pm = ParticleMesh(BoxSize=8.0, Nmesh=(4, 4, 4), dtype='f8')
engine = FastPMEngine(pm, shift=0.5, B=1)
code = CodeSegment(engine)
code.create_linear_field(whitenoise='whitenoise',
powerspectrum=pk,
dlinear_k='dlinear_k')
code.solve_fastpm(pt=pt,
dlinear_k='dlinear_k',
asteps=[0.1, 1.0],
s='s',
v='v',
s1='s1',
s2='s2')
# code.solve_fastpm(pt=pt, dlinear_k='dlinear_k', asteps=[1.0], s='s', v='v', s1='s1', s2='s2')
code.get_x(s='s', x='x')
code.paint_simple(x='x', density='density')
field = pm.generate_whitenoise(seed=1234, unitary=True).c2r()
eps = field.cnorm()**0.5 * 1e-5
check_grad(code,
's1',
'whitenoise',
init={'whitenoise': field},
eps=eps,
rtol=1e-8)
check_grad(code,
's',
'whitenoise',
init={'whitenoise': field},
eps=eps,
rtol=1e-8)
check_grad(code,
'v',
'whitenoise',
init={'whitenoise': field},
eps=eps,
rtol=1e-8)
check_grad(code,
'density',
'whitenoise',
init={'whitenoise': field},
eps=eps,
rtol=1e-8)
