def _create_split_complex_pointer(array_real, array_imag, double = False):
"""Creates a split-complex data pointer from two real numpy arrays"""
_array_real = ffi.from_buffer(array_real)
_array_imag = ffi.from_buffer(array_imag)
if double:
split_complex_pointer = ffi.new("DSPDoubleSplitComplex*")
split_complex_pointer.realp = ffi.cast("double*",_array_real)
split_complex_pointer.imagp = ffi.cast("double*",_array_imag)
else:
split_complex_pointer = ffi.new("DSPSplitComplex*")
split_complex_pointer.realp = ffi.cast("float*",_array_real)
split_complex_pointer.imagp = ffi.cast("float*",_array_imag)
return split_complex_pointer
def _fft(setup, a, out, n = 1, dim = 1, direction = +1, real_transform = False):
"""1D or 2D fft transform, real or complex"""
#initialize
_a = ffi.from_buffer(a)
_pa = ffi.cast(setup.cast_name,_a)
_ps = setup.split_complex_pointer
_out = ffi.from_buffer(out)
_pout = ffi.cast(setup.cast_name,_out)
#define functions
_ctoz, _ztoc = (lib.vDSP_ctozD, lib.vDSP_ztocD) if setup.double else (lib.vDSP_ctoz, lib.vDSP_ztoc)
_func = _get_vDSP_fft_inplace(double = setup.double, dim = dim, real_transform = real_transform)
#perform calculations
_ctoz(_pa,2,_ps,1, setup.count)
if dim == 1:
_func(setup.pointer, _ps, 1, setup.count//n, setup.size[0], n , direction)
else:
_func(setup.pointer, _ps, 1, 0, setup.size[0], setup.size[1], direction)
_ztoc(_ps,1,_pout,2, setup.count)
def _sffto(setup, ar, ai, out, n = 1, dim = 1, direction = +1, real_transform = False):
"""1D or 2D fft transform, real or complex for split-complex input data - out of place"""
_ps = _create_split_complex_pointer(ar, ai, double = setup.double)
_out = ffi.from_buffer(out)
_pout = ffi.cast(setup.cast_name,_out)
_pouts = setup.split_complex_pointer
_func = _get_vDSP_fft_outplace(double = setup.double, dim = dim, real_transform = real_transform)
if dim == 1:
_func(setup.pointer, _ps, 1, setup.count//n,_pouts, 1, setup.count//n, setup.size[0], n, direction)
else:
_func(setup.pointer, _ps, 1,0, _pouts, 1,0,setup.size[0], setup.size[1],direction)
_ztoc = lib.vDSP_ztocD if setup.double else lib.vDSP_ztoc
_ztoc(_pouts,1,_pout,2, setup.count)
def _sffti(setup, ar, ai, out, n = 1, dim = 1, direction = +1, real_transform = False):
"""1D or 2D fft transform, real or complex for split-complex input data - inplace"""
#initialize
_ps = _create_split_complex_pointer(ar, ai, double = setup.double)
_out = ffi.from_buffer(out)
_pout = ffi.cast(setup.cast_name,_out)
#define functions
_ztoc = lib.vDSP_ztocD if setup.double else lib.vDSP_ztoc
_func = _get_vDSP_fft_inplace(double = setup.double, dim = dim, real_transform = real_transform)
#perform calculations
if dim == 1:
_func(setup.pointer, _ps, 1, setup.count//n, setup.size[0], n , direction)
else:
_func(setup.pointer, _ps, 1, 0, setup.size[0], setup.size[1], direction)
_ztoc(_ps,1,_pout,2, setup.count)
def _ffts(setup, a, outr, outi, n = 1, dim = 1, direction = +1, real_transform = False):
"""Same as _fft, but it leaves the data in split-complex format"""
#initialize
_a = ffi.from_buffer(a)
_pa = ffi.cast(setup.cast_name,_a)
_ps = _create_split_complex_pointer(outr, outi, double = setup.double)
#define functions
_ctoz= lib.vDSP_ctozD if setup.double else lib.vDSP_ctoz
_func = _get_vDSP_fft_inplace(double = setup.double, dim = dim, real_transform = real_transform)
#perform calculations
_ctoz(_pa,2,_ps,1, setup.count)
if dim == 1:
_func(setup.pointer, _ps, 1, setup.count//n, setup.size[0], n, direction)
else:
_func(setup.pointer, _ps, 1,0, setup.size[0], setup.size[1],direction)