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#!/usr/bin/env python
import os
import pickle
import numpy as np
from numpy.testing import (assert_allclose, assert_, assert_raises,
assert_equal)
import pywt
def test_traversing_tree_2d():
x = np.array([[1, 2, 3, 4, 5, 6, 7, 8]] * 8, dtype=np.float64)
wp = pywt.WaveletPacket2D(data=x, wavelet='db1', mode='symmetric')
assert_(np.all(wp.data == x))
assert_(wp.path == '')
assert_(wp.level == 0)
assert_(wp.maxlevel == 3)
assert_allclose(wp['a'].data, np.array([[3., 7., 11., 15.]] * 4),
rtol=1e-12)
assert_allclose(wp['h'].data, np.zeros((4, 4)), rtol=1e-12, atol=1e-14)
assert_allclose(wp['v'].data, -np.ones((4, 4)), rtol=1e-12, atol=1e-14)
assert_allclose(wp['d'].data, np.zeros((4, 4)), rtol=1e-12, atol=1e-14)
assert_allclose(wp['aa'].data, np.array([[10., 26.]] * 2), rtol=1e-12)
assert_(wp['a']['a'].data is wp['aa'].data)
assert_allclose(wp['aaa'].data, np.array([[36.]]), rtol=1e-12)
assert_raises(IndexError, lambda: wp['aaaa'])
assert_raises(ValueError, lambda: wp['f'])
def test_accessing_node_attributes_2d():
x = np.array([[1, 2, 3, 4, 5, 6, 7, 8]] * 8, dtype=np.float64)
wp = pywt.WaveletPacket2D(data=x, wavelet='db1', mode='symmetric')
assert_allclose(wp['av'].data, np.zeros((2, 2)) - 4, rtol=1e-12)
assert_(wp['av'].path == 'av')
assert_(wp['av'].node_name == 'v')
assert_(wp['av'].parent.path == 'a')
assert_allclose(wp['av'].parent.data, np.array([[3., 7., 11., 15.]] * 4),
rtol=1e-12)
# can also index via a tuple instead of concatenated strings
assert_(wp['av'].level == 2)
assert_(wp['av'].maxlevel == 3)
assert_(wp['av'].mode == 'symmetric')
# tuple-based access is also supported
node = wp[('a', 'v')]
# can access a node's path as either a single string or in tuple form
assert_(node.path == 'av')
assert_(node.path_tuple == ('a', 'v'))
def test_collecting_nodes_2d():
x = np.array([[1, 2, 3, 4, 5, 6, 7, 8]] * 8, dtype=np.float64)
wp = pywt.WaveletPacket2D(data=x, wavelet='db1', mode='symmetric')
assert_(len(wp.get_level(0)) == 1)
assert_(wp.get_level(0)[0].path == '')
# First level
assert_(len(wp.get_level(1)) == 4)
assert_([node.path for node in wp.get_level(1)] == ['a', 'h', 'v', 'd'])
# Second level
assert_(len(wp.get_level(2)) == 16)
paths = [node.path for node in wp.get_level(2)]
expected_paths = ['aa', 'ah', 'av', 'ad', 'ha', 'hh', 'hv', 'hd', 'va',
'vh', 'vv', 'vd', 'da', 'dh', 'dv', 'dd']
assert_(paths == expected_paths)
# Third level.
assert_(len(wp.get_level(3)) == 64)
paths = [node.path for node in wp.get_level(3)]
expected_paths = ['aaa', 'aah', 'aav', 'aad', 'aha', 'ahh', 'ahv', 'ahd',
'ava', 'avh', 'avv', 'avd', 'ada', 'adh', 'adv', 'add',
'haa', 'hah', 'hav', 'had', 'hha', 'hhh', 'hhv', 'hhd',
'hva', 'hvh', 'hvv', 'hvd', 'hda', 'hdh', 'hdv', 'hdd',
'vaa', 'vah', 'vav', 'vad', 'vha', 'vhh', 'vhv', 'vhd',
'vva', 'vvh', 'vvv', 'vvd', 'vda', 'vdh', 'vdv', 'vdd',
'daa', 'dah', 'dav', 'dad', 'dha', 'dhh', 'dhv', 'dhd',
'dva', 'dvh', 'dvv', 'dvd', 'dda', 'ddh', 'ddv', 'ddd']
assert_(paths == expected_paths)
# test 2D frequency ordering at the first level
fnodes = wp.get_level(1, order='freq')
assert_(fnodes[0][0].path == 'a')
assert_(fnodes[0][1].path == 'v')
assert_(fnodes[1][0].path == 'h')
assert_(fnodes[1][1].path == 'd')
# test 2D frequency ordering at the second level
fnodes = wp.get_level(2, order='freq')
assert_([n.path for n in fnodes[0]] == ['aa', 'av', 'vv', 'va'])
assert_([n.path for n in fnodes[1]] == ['ah', 'ad', 'vd', 'vh'])
assert_([n.path for n in fnodes[2]] == ['hh', 'hd', 'dd', 'dh'])
assert_([n.path for n in fnodes[3]] == ['ha', 'hv', 'dv', 'da'])
# invalid node collection order
assert_raises(ValueError, wp.get_level, 2, 'invalid_order')
def test_data_reconstruction_2d():
x = np.array([[1, 2, 3, 4, 5, 6, 7, 8]] * 8, dtype=np.float64)
wp = pywt.WaveletPacket2D(data=x, wavelet='db1', mode='symmetric')
new_wp = pywt.WaveletPacket2D(data=None, wavelet='db1', mode='symmetric')
new_wp['vh'] = wp['vh'].data
new_wp['vv'] = wp['vh'].data
new_wp['vd'] = np.zeros((2, 2), dtype=np.float64)
new_wp['a'] = [[3.0, 7.0, 11.0, 15.0]] * 4
new_wp['d'] = np.zeros((4, 4), dtype=np.float64)
new_wp['h'] = wp['h'] # all zeros
assert_allclose(new_wp.reconstruct(update=False),
np.array([[1.5, 1.5, 3.5, 3.5, 5.5, 5.5, 7.5, 7.5]] * 8),
rtol=1e-12)
assert_allclose(wp['va'].data, np.zeros((2, 2)) - 2, rtol=1e-12)
new_wp['va'] = wp['va'].data
assert_allclose(new_wp.reconstruct(update=False), x, rtol=1e-12)
def test_data_reconstruction_delete_nodes_2d():
x = np.array([[1, 2, 3, 4, 5, 6, 7, 8]] * 8, dtype=np.float64)
wp = pywt.WaveletPacket2D(data=x, wavelet='db1', mode='symmetric')
new_wp = pywt.WaveletPacket2D(data=None, wavelet='db1', mode='symmetric')
new_wp['vh'] = wp['vh'].data
new_wp['vv'] = wp['vh'].data
new_wp['vd'] = np.zeros((2, 2), dtype=np.float64)
new_wp['a'] = [[3.0, 7.0, 11.0, 15.0]] * 4
new_wp['d'] = np.zeros((4, 4), dtype=np.float64)
new_wp['h'] = wp['h'] # all zeros
assert_allclose(new_wp.reconstruct(update=False),
np.array([[1.5, 1.5, 3.5, 3.5, 5.5, 5.5, 7.5, 7.5]] * 8),
rtol=1e-12)
new_wp['va'] = wp['va'].data
assert_allclose(new_wp.reconstruct(update=False), x, rtol=1e-12)
del(new_wp['va'])
# TypeError on accessing deleted node
assert_raises(TypeError, lambda: new_wp['va'])
new_wp['va'] = wp['va'].data
assert_(new_wp.data is None)
assert_allclose(new_wp.reconstruct(update=True), x, rtol=1e-12)
assert_allclose(new_wp.data, x, rtol=1e-12)
# TODO: decompose=True
def test_lazy_evaluation_2D():
# Note: internal implementation detail not to be relied on. Testing for
# now for backwards compatibility, but this test may be broken in needed.
x = np.array([[1, 2, 3, 4, 5, 6, 7, 8]] * 8)
wp = pywt.WaveletPacket2D(data=x, wavelet='db1', mode='symmetric')
assert_(wp.a is None)
assert_allclose(wp['a'].data, np.array([[3., 7., 11., 15.]] * 4),
rtol=1e-12)
assert_allclose(wp.a.data, np.array([[3., 7., 11., 15.]] * 4), rtol=1e-12)
assert_allclose(wp.d.data, np.zeros((4, 4)), rtol=1e-12, atol=1e-12)
def test_wavelet_packet_dtypes():
shape = (16, 16)
for dtype in [np.float32, np.float64, np.complex64, np.complex128]:
x = np.random.randn(*shape).astype(dtype)
if np.iscomplexobj(x):
x = x + 1j*np.random.randn(*shape).astype(x.real.dtype)
wp = pywt.WaveletPacket2D(data=x, wavelet='db1', mode='symmetric')
# no unnecessary copy made
assert_(wp.data is x)
# assigning to a node should not change supported dtypes
wp['d'] = wp['d'].data
assert_equal(wp['d'].data.dtype, x.dtype)
# full decomposition
wp.get_level(wp.maxlevel)
# reconstruction from coefficients should preserve dtype
r = wp.reconstruct(False)
assert_equal(r.dtype, x.dtype)
assert_allclose(r, x, atol=1e-5, rtol=1e-5)
def test_2d_roundtrip():
# test case corresponding to PyWavelets issue 447
original = pywt.data.camera()
wp = pywt.WaveletPacket2D(data=original, wavelet='db3', mode='smooth',
maxlevel=3)
r = wp.reconstruct()
assert_allclose(original, r, atol=1e-12, rtol=1e-12)
def test_wavelet_packet_axes():
rstate = np.random.RandomState(0)
shape = (32, 16)
x = rstate.standard_normal(shape)
for axes in [(0, 1), (1, 0), (-2, 1)]:
wp = pywt.WaveletPacket2D(data=x, wavelet='db1', mode='symmetric',
axes=axes)
# partial decomposition
nodes = wp.get_level(2)
# size along the transformed axes has changed
for ax2 in range(x.ndim):
if ax2 in tuple(np.asarray(axes) % x.ndim):
nodes[0].data.shape[ax2] < x.shape[ax2]
else:
nodes[0].data.shape[ax2] == x.shape[ax2]
# recontsruction from coefficients should preserve dtype
r = wp.reconstruct(False)
assert_equal(r.dtype, x.dtype)
assert_allclose(r, x, atol=1e-12, rtol=1e-12)
# must have two non-duplicate axes
assert_raises(ValueError, pywt.WaveletPacket2D, data=x, wavelet='db1',
axes=(0, 0))
assert_raises(ValueError, pywt.WaveletPacket2D, data=x, wavelet='db1',
axes=(0, ))
assert_raises(ValueError, pywt.WaveletPacket2D, data=x, wavelet='db1',
axes=(0, 1, 2))
def test_wavelet_packet2d_pickle(tmpdir):
packet = pywt.WaveletPacket2D(np.arange(256).reshape(16, 16), 'sym4')
filename = os.path.join(tmpdir, 'wp2d.pickle')
with open(filename, 'wb') as f:
pickle.dump(packet, f)
with open(filename, 'rb') as f:
packet2 = pickle.load(f)
assert isinstance(packet2, pywt.WaveletPacket2D)
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