ref: 6e157df38d1a9acb48810660b7b8f1a9e7d87a7e
dir: /python/tests/test_dct.py/
#! /usr/bin/env python
import numpy as np
from numpy.testing import TestCase, assert_almost_equal
import aubio
precomputed_arange = [ 9.89949512, -6.44232273, 0., -0.67345482, 0.,
-0.20090288, 0., -0.05070186]
precomputed_some_ones = [ 4.28539848, 0.2469689, -0.14625292, -0.58121818,
-0.83483052, -0.75921834, -0.35168475, 0.24087936,
0.78539824, 1.06532764, 0.97632152, 0.57164496, 0.03688532,
-0.39446154, -0.54619485, -0.37771079]
class aubio_dct(TestCase):
def test_init(self):
""" test that aubio.dct() is created with expected size """
a_dct = aubio.dct()
self.assertEqual(a_dct.size, 1024)
def test_arange(self):
""" test that dct(arange(8)) is computed correctly
>>> from scipy.fftpack import dct
>>> a_in = np.arange(8).astype(aubio.float_type)
>>> precomputed = dct(a_in, norm='ortho')
"""
N = len(precomputed_arange)
a_dct = aubio.dct(8)
a_in = np.arange(8).astype(aubio.float_type)
a_expected = aubio.fvec(precomputed_arange)
assert_almost_equal(a_dct(a_in), a_expected, decimal=5)
def test_some_ones(self):
""" test that dct(somevector) is computed correctly """
a_dct = aubio.dct(16)
a_in = np.ones(16).astype(aubio.float_type)
a_in[1] = 0
a_in[3] = np.pi
a_expected = aubio.fvec(precomputed_some_ones)
assert_almost_equal(a_dct(a_in), a_expected, decimal=6)
def test_reconstruction(self):
""" test that some_ones vector can be recontructed """
a_dct = aubio.dct(16)
a_in = np.ones(16).astype(aubio.float_type)
a_in[1] = 0
a_in[3] = np.pi
a_dct_in = a_dct(a_in)
a_dct_reconstructed = a_dct.rdo(a_dct_in)
assert_almost_equal(a_dct_reconstructed, a_in, decimal=6)
def test_negative_size(self):
""" test that creation fails with a negative size """
with self.assertRaises(ValueError):
aubio.dct(-1)
def test_wrong_size(self):
""" test that creation fails with a non power-of-two size """
# supports for non 2** fft sizes only when compiled with fftw3
size = 13
try:
with self.assertRaises(RuntimeError):
aubio.dct(size)
except AssertionError:
self.skipTest('creating aubio.dct with size %d did not fail' % size)