def finufft2d1(x,
y,
c,
isign,
eps,
ms,
mt,
f,
debug=0,
spread_debug=0,
spread_sort=1,
fftw=0,
modeord=0,
chkbnds=1):
"""2D type-1 (aka adjoint) complex nonuniform fast Fourier transform
nj
f(k1,k2) = SUM c[j] exp(+/-i (k1 x(j) + k2 y[j])),
j=1
for -ms/2 <= k1 <= (ms-1)/2, -mt/2 <= k2 <= (mt-1)/2
Inputs:
x (float[nj]): nonuniform source x-coords, valid only in [-3pi,3pi]
y (float[nj]): nonuniform source y-coords, valid only in [-3pi,3pi]
c (complex[nj]): source strengths
isign (int): if >=0, uses + sign in exponential, otherwise - sign.
eps (float): precision requested (>1e-16)
ms,mt (int): numbers of Fourier modes requested in x- and y-
directions. Each may be even or odd;
in either case the modes are integers lying in [-m/2, (m-1)/2]
Optional inputs:
debug (int): 0 (silent), 1 (print timing breakdown).
spread_debug (int): 0 (spreader silent), 1, 2... (print spreader info)
spread_sort (int): 0 (don't sort NU pts in spreader), 1 (sort)
fftw (int): 0 (use FFTW_ESTIMATE), 1 (use FFTW_MEASURE), ...
modeord (int): 0 (CMCL increasing mode ordering), 1 (FFT ordering)
chkbnds (int): 0 (don't check NU points valid), 1 (do).
Outputs:
f (complex[ms,mt]): Fourier mode values, stored ms fastest.
mode ordering in each dimension given by modeord.
Returns:
error status, 0 : success
1 : eps too small
2 : size of arrays to malloc exceed MAX_NF
4 : if chkbnds, at least one NU point out of range
Example:
see python_tests/accuracy_speed_tests.py
"""
# f is the output and must have dtype=np.complex128
x = x.astype(np.float64, copy=False) #copies only if type changes
y = y.astype(np.float64, copy=False) #copies only if type changes
c = c.astype(np.complex128, copy=False) #copies only if type changes
return finufftpy_cpp.finufft2d1_cpp(x, y, c, isign, eps, ms, mt, f, debug,
spread_debug, spread_sort, fftw,
modeord, chkbnds)
def nufft2d1(x,y,c,isign,eps,ms,mt,f,debug=0,spread_debug=0,spread_sort=2,fftw=0,modeord=0,chkbnds=1,upsampfac=2.0):
"""2D type-1 (aka adjoint) complex nonuniform fast Fourier transform
::
nj-1
f(k1,k2) = SUM c[j] exp(+/-i (k1 x(j) + k2 y[j])),
j=0
for -ms/2 <= k1 <= (ms-1)/2, -mt/2 <= k2 <= (mt-1)/2
Args:
x (float[nj]): nonuniform source x-coords, valid only in [-3pi,3pi]
y (float[nj]): nonuniform source y-coords, valid only in [-3pi,3pi]
c (complex[nj]): source strengths
isign (int): if >=0, uses + sign in exponential, otherwise - sign
eps (float): precision requested (>1e-16)
ms (int): number of Fourier modes in x-direction, may be even or odd;
in either case the modes are integers lying in [-ms/2, (ms-1)/2]
mt (int): number of Fourier modes in y-direction, may be even or odd;
in either case the modes are integers lying in [-mt/2, (mt-1)/2]
f (complex[ms,mt]): output Fourier mode values. Should be initialized as a Fortran-ordered (ie ms fast, mt slow) numpy array of the correct size
debug (int, optional): 0 (silent), 1 (print timing breakdown)
spread_debug (int, optional): 0 (silent), 1, 2... (prints spreader info)
spread_sort (int, optional): 0 (don't sort NU pts in spreader), 1 (sort),
2 (heuristic decision to sort)
fftw (int, optional): 0 (use FFTW_ESTIMATE), 1 (use FFTW_MEASURE)
modeord (int, optional): 0 (CMCL increasing mode ordering), 1 (FFT ordering)
chkbnds (int, optional): 0 (don't check NU points valid), 1 (do)
upsampfac (float): either 2.0 (default), or 1.25 (low RAM & small FFT size)
.. note::
The output is written into the f array.
Returns:
int: 0 if success, 1 if eps too small,
2 if size of arrays to malloc exceed MAX_NF,
4 at least one NU point out of range (if chkbnds true)
Example:
see ``python/tests/accuracy_speed_tests.py``
"""
# f is the output and must have dtype=np.complex128
x=x.astype(np.float64,copy=False) #copies only if type changes
y=y.astype(np.float64,copy=False) #copies only if type changes
c=c.astype(np.complex128,copy=False) #copies only if type changes
return finufftpy_cpp.finufft2d1_cpp(x,y,c,isign,eps,ms,mt,f,debug,spread_debug,spread_sort,fftw,modeord,chkbnds,upsampfac)