102 lines
3.4 KiB
Python
102 lines
3.4 KiB
Python
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# Copyright (c) 2017 The PyWavelets Developers
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# <https://github.com/PyWavelets/pywt>
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# See COPYING for license details.
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import inspect
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import numpy as np
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import sys
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from collections.abc import Iterable
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from ._extensions._pywt import (Wavelet, ContinuousWavelet,
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DiscreteContinuousWavelet, Modes)
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# define string_types as in six for Python 2/3 compatibility
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if sys.version_info[0] == 3:
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string_types = str,
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else:
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string_types = basestring,
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def _as_wavelet(wavelet):
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"""Convert wavelet name to a Wavelet object."""
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if not isinstance(wavelet, (ContinuousWavelet, Wavelet)):
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wavelet = DiscreteContinuousWavelet(wavelet)
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if isinstance(wavelet, ContinuousWavelet):
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raise ValueError(
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"A ContinuousWavelet object was provided, but only discrete "
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"Wavelet objects are supported by this function. A list of all "
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"supported discrete wavelets can be obtained by running:\n"
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"print(pywt.wavelist(kind='discrete'))")
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return wavelet
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def _wavelets_per_axis(wavelet, axes):
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"""Initialize Wavelets for each axis to be transformed.
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Parameters
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----------
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wavelet : Wavelet or tuple of Wavelets
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If a single Wavelet is provided, it will used for all axes. Otherwise
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one Wavelet per axis must be provided.
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axes : list
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The tuple of axes to be transformed.
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Returns
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-------
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wavelets : list of Wavelet objects
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A tuple of Wavelets equal in length to ``axes``.
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"""
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axes = tuple(axes)
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if isinstance(wavelet, string_types + (Wavelet, )):
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# same wavelet on all axes
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wavelets = [_as_wavelet(wavelet), ] * len(axes)
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elif isinstance(wavelet, Iterable):
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# (potentially) unique wavelet per axis (e.g. for dual-tree DWT)
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if len(wavelet) == 1:
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wavelets = [_as_wavelet(wavelet[0]), ] * len(axes)
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else:
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if len(wavelet) != len(axes):
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raise ValueError((
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"The number of wavelets must match the number of axes "
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"to be transformed."))
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wavelets = [_as_wavelet(w) for w in wavelet]
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else:
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raise ValueError("wavelet must be a str, Wavelet or iterable")
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return wavelets
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def _modes_per_axis(modes, axes):
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"""Initialize mode for each axis to be transformed.
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Parameters
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----------
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modes : str or tuple of strings
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If a single mode is provided, it will used for all axes. Otherwise
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one mode per axis must be provided.
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axes : tuple
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The tuple of axes to be transformed.
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Returns
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-------
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modes : tuple of int
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A tuple of Modes equal in length to ``axes``.
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"""
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axes = tuple(axes)
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if isinstance(modes, string_types + (int, )):
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# same wavelet on all axes
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modes = [Modes.from_object(modes), ] * len(axes)
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elif isinstance(modes, Iterable):
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if len(modes) == 1:
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modes = [Modes.from_object(modes[0]), ] * len(axes)
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else:
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# (potentially) unique wavelet per axis (e.g. for dual-tree DWT)
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if len(modes) != len(axes):
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raise ValueError(("The number of modes must match the number "
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"of axes to be transformed."))
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modes = [Modes.from_object(mode) for mode in modes]
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else:
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raise ValueError("modes must be a str, Mode enum or iterable")
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return modes
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