111 lines
3.2 KiB
Python
111 lines
3.2 KiB
Python
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import numpy as np
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from . import pypocketfft as pfft
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from .helper import (_asfarray, _init_nd_shape_and_axes, _datacopied,
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_fix_shape, _fix_shape_1d, _normalization, _workers)
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import functools
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def _r2r(forward, transform, x, type=2, n=None, axis=-1, norm=None,
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overwrite_x=False, workers=None):
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"""Forward or backward 1-D DCT/DST
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Parameters
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----------
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forward: bool
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Transform direction (determines type and normalisation)
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transform: {pypocketfft.dct, pypocketfft.dst}
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The transform to perform
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"""
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tmp = _asfarray(x)
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overwrite_x = overwrite_x or _datacopied(tmp, x)
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norm = _normalization(norm, forward)
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workers = _workers(workers)
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if not forward:
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if type == 2:
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type = 3
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elif type == 3:
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type = 2
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if n is not None:
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tmp, copied = _fix_shape_1d(tmp, n, axis)
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overwrite_x = overwrite_x or copied
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elif tmp.shape[axis] < 1:
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raise ValueError("invalid number of data points ({0}) specified"
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.format(tmp.shape[axis]))
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out = (tmp if overwrite_x else None)
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# For complex input, transform real and imaginary components separably
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if np.iscomplexobj(x):
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out = np.empty_like(tmp) if out is None else out
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transform(tmp.real, type, (axis,), norm, out.real, workers)
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transform(tmp.imag, type, (axis,), norm, out.imag, workers)
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return out
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return transform(tmp, type, (axis,), norm, out, workers)
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dct = functools.partial(_r2r, True, pfft.dct)
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dct.__name__ = 'dct'
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idct = functools.partial(_r2r, False, pfft.dct)
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idct.__name__ = 'idct'
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dst = functools.partial(_r2r, True, pfft.dst)
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dst.__name__ = 'dst'
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idst = functools.partial(_r2r, False, pfft.dst)
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idst.__name__ = 'idst'
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def _r2rn(forward, transform, x, type=2, s=None, axes=None, norm=None,
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overwrite_x=False, workers=None):
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"""Forward or backward nd DCT/DST
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Parameters
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----------
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forward: bool
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Transform direction (determines type and normalisation)
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transform: {pypocketfft.dct, pypocketfft.dst}
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The transform to perform
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"""
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tmp = _asfarray(x)
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shape, axes = _init_nd_shape_and_axes(tmp, s, axes)
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overwrite_x = overwrite_x or _datacopied(tmp, x)
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if len(axes) == 0:
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return x
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tmp, copied = _fix_shape(tmp, shape, axes)
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overwrite_x = overwrite_x or copied
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if not forward:
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if type == 2:
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type = 3
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elif type == 3:
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type = 2
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norm = _normalization(norm, forward)
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workers = _workers(workers)
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out = (tmp if overwrite_x else None)
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# For complex input, transform real and imaginary components separably
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if np.iscomplexobj(x):
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out = np.empty_like(tmp) if out is None else out
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transform(tmp.real, type, axes, norm, out.real, workers)
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transform(tmp.imag, type, axes, norm, out.imag, workers)
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return out
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return transform(tmp, type, axes, norm, out, workers)
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dctn = functools.partial(_r2rn, True, pfft.dct)
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dctn.__name__ = 'dctn'
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idctn = functools.partial(_r2rn, False, pfft.dct)
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idctn.__name__ = 'idctn'
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dstn = functools.partial(_r2rn, True, pfft.dst)
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dstn.__name__ = 'dstn'
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idstn = functools.partial(_r2rn, False, pfft.dst)
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idstn.__name__ = 'idstn'
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