def qapamfft_from_etafft(self, eta_fft, params=None):
"""eta (fft) ---> q, ap, am (fft)"""
if params is None:
params = self.params
q_fft = -params.f * eta_fft
ap_fft = 0.5 * laplacian_fft(eta_fft, self.K2)
am_fft = ap_fft.copy()
return q_fft, ap_fft, am_fft
def afft_from_uxuyetafft(self, ux_fft, uy_fft, eta_fft, params=None):
if params is None:
params = self.params
a_fft = laplacian_fft(eta_fft, self.K2)
if params.f != 0:
rot_fft = self.rotfft_from_vecfft(ux_fft, uy_fft)
a_fft += params.f / params.c2 * rot_fft
return a_fft
def qdafft_from_uxuyetafft(self, ux_fft, uy_fft, eta_fft, params=None):
if params is None:
params = self.params
div_fft = self.divfft_from_vecfft(ux_fft, uy_fft)
rot_fft = self.rotfft_from_vecfft(ux_fft, uy_fft)
q_fft = rot_fft - params.f * eta_fft
ageo_fft = params.f / params.c2 * rot_fft + laplacian_fft(
eta_fft, self.K2
)
return q_fft, div_fft, ageo_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 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