/usr/lib/python3/dist-packages/dtcwt/coeffs.py is in python3-dtcwt 0.12.0-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 | """Functions to load standard wavelet coefficients.
"""
from __future__ import absolute_import
import os
from numpy import load
DATADIR = os.path.join(os.path.dirname(__file__), 'data')
COEFF_CACHE = {}
def _load_from_file(basename, varnames):
filename = os.path.join(DATADIR, basename + '.npz')
try:
mat = COEFF_CACHE[filename]
except KeyError:
mat = load(filename)
COEFF_CACHE[filename] = mat
try:
return tuple(mat[k] for k in varnames)
except KeyError:
raise ValueError('Wavelet does not define ({0}) coefficients'.format(', '.join(varnames)))
def biort(name):
"""Load level 1 wavelet by name.
:param name: a string specifying the wavelet family name
:returns: a tuple of vectors giving filter coefficients
============= ============================================
Name Wavelet
============= ============================================
antonini Antonini 9,7 tap filters.
legall LeGall 5,3 tap filters.
near_sym_a Near-Symmetric 5,7 tap filters.
near_sym_b Near-Symmetric 13,19 tap filters.
near_sym_b_bp Near-Symmetric 13,19 tap filters + BP filter
============= ============================================
Return a tuple whose elements are a vector specifying the h0o, g0o, h1o and
g1o coefficients.
See :ref:`rot-symm-wavelets` for an explanation of the ``near_sym_b_bp``
wavelet filters.
:raises IOError: if name does not correspond to a set of wavelets known to the library.
:raises ValueError: if name specifies a :py:func:`dtcwt.coeffs.qshift` wavelet.
"""
if name == 'near_sym_b_bp':
return _load_from_file(name, ('h0o', 'g0o', 'h1o', 'g1o', 'h2o', 'g2o'))
else:
return _load_from_file(name, ('h0o', 'g0o', 'h1o', 'g1o'))
def qshift(name):
"""Load level >=2 wavelet by name,
:param name: a string specifying the wavelet family name
:returns: a tuple of vectors giving filter coefficients
============ ============================================
Name Wavelet
============ ============================================
qshift_06 Quarter Sample Shift Orthogonal (Q-Shift) 10,10 tap filters,
(only 6,6 non-zero taps).
qshift_a Q-shift 10,10 tap filters,
(with 10,10 non-zero taps, unlike qshift_06).
qshift_b Q-Shift 14,14 tap filters.
qshift_c Q-Shift 16,16 tap filters.
qshift_d Q-Shift 18,18 tap filters.
qshift_b_bp Q-Shift 18,18 tap filters + BP
============ ============================================
Return a tuple whose elements are a vector specifying the h0a, h0b, g0a,
g0b, h1a, h1b, g1a and g1b coefficients.
See :ref:`rot-symm-wavelets` for an explanation of the ``qshift_b_bp``
wavelet filters.
:raises IOError: if name does not correspond to a set of wavelets known to the library.
:raises ValueError: if name specifies a :py:func:`dtcwt.coeffs.biort` wavelet.
"""
if name == 'qshift_b_bp':
return _load_from_file(name, ('h0a', 'h0b', 'g0a', 'g0b', 'h1a', 'h1b', 'g1a', 'g1b', 'h2a', 'h2b', 'g2a','g2b'))
else:
return _load_from_file(name, ('h0a', 'h0b', 'g0a', 'g0b', 'h1a', 'h1b', 'g1a', 'g1b'))
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