def etafft_from_aqfft(self, a_fft, q_fft, params=None):
"""Compute eta in Fourier space."""
if params is None:
params = self.params
Kappa2_not0 = self.Kappa2_not0
else:
Kappa2_not0 = self.K2_not0 + params.kd2
if params.f == 0:
eta_fft = invlaplacian_fft(a_fft, self.K2_not0, rank)
else:
eta_fft = invlaplacian_fft(
(a_fft - params.f / params.c2 * q_fft), Kappa2_not0, rank
)
return eta_fft
def etafft_from_afft(self, a_fft, params=None):
"""Compute eta in Fourier space."""
if params is None:
params = self.params
Kappa2_not0 = self.Kappa2_not0
else:
Kappa2_not0 = self.K2_not0 + params.kd2
eta_fft = invlaplacian_fft(a_fft, Kappa2_not0, rank)
return eta_fft
def rotfft_from_qfft(self, q_fft, params=None):
"""Compute ux, uy and eta in Fourier space."""
if params is None:
params = self.params
Kappa2_not0 = self.Kappa2_not0
else:
Kappa2_not0 = self.K2_not0 + params.kd2
rot_fft = laplacian_fft(
invlaplacian_fft(q_fft, Kappa2_not0, rank), self.K2
)
return rot_fft
def etafft_from_qfft(self, q_fft, params=None):
"""Compute eta in Fourier space."""
if params is None:
params = self.params
Kappa2_not0 = self.Kappa2_not0
else:
Kappa2_not0 = self.K2_not0 + params.kd2
if params.f == 0:
eta_fft = self.create_arrayK(value=0)
else:
eta_fft = (
-params.f / params.c2 * invlaplacian_fft(q_fft, Kappa2_not0, rank)
)
return eta_fft
def uxuyetafft_from_qfft(self, q_fft, params=None):
"""Compute ux, uy and eta in Fourier space."""
if params is None:
params = self.params
Kappa2_not0 = self.Kappa2_not0
else:
Kappa2_not0 = self.K2_not0 + params.kd2
ilq_fft = invlaplacian_fft(q_fft, Kappa2_not0, rank)
rot_fft = laplacian_fft(ilq_fft, self.K2)
ux_fft, uy_fft = self.vecfft_from_rotfft(rot_fft)
if params.f == 0:
eta_fft = self.create_arrayK(value=0)
else:
eta_fft = -params.f * ilq_fft / params.c2
return ux_fft, uy_fft, eta_fft