python/tests/test_dct.py

   1 #! /usr/bin/env python
   2
   3
   4 import numpy as np
   5 from numpy.testing import TestCase, assert_almost_equal
   6 import aubio
   7
   8 precomputed_arange = [ 9.89949512, -6.44232273,  0., -0.67345482, 0.,
   9         -0.20090288, 0., -0.05070186]
  10
  11 precomputed_some_ones = [ 4.28539848,  0.2469689,  -0.14625292, -0.58121818,
  12         -0.83483052, -0.75921834, -0.35168475,  0.24087936,
  13         0.78539824, 1.06532764,  0.97632152,  0.57164496, 0.03688532,
  14         -0.39446154, -0.54619485, -0.37771079]
  15
  16 class aubio_dct(TestCase):
  17
  18     def test_init(self):
  19         """ test that aubio.dct() is created with expected size """
  20         a_dct = aubio.dct()
  21         self.assertEqual(a_dct.size, 1024)
  22
  23     def test_arange(self):
  24         """ test that dct(arange(8)) is computed correctly
  25
  26         >>> from scipy.fftpack import dct
  27         >>> a_in = np.arange(8).astype(aubio.float_type)
  28         >>> precomputed = dct(a_in, norm='ortho')
  29         """
  30         N = len(precomputed_arange)
  31         a_dct = aubio.dct(8)
  32         a_in = np.arange(8).astype(aubio.float_type)
  33         a_expected = aubio.fvec(precomputed_arange)
  34         assert_almost_equal(a_dct(a_in), a_expected, decimal=5)
  35
  36     def test_some_ones(self):
  37         """ test that dct(somevector) is computed correctly """
  38         a_dct = aubio.dct(16)
  39         a_in = np.ones(16).astype(aubio.float_type)
  40         a_in[1] = 0
  41         a_in[3] = np.pi
  42         a_expected = aubio.fvec(precomputed_some_ones)
  43         assert_almost_equal(a_dct(a_in), a_expected, decimal=6)
  44
  45     def test_reconstruction(self):
  46         """ test that some_ones vector can be recontructed """
  47         a_dct = aubio.dct(16)
  48         a_in = np.ones(16).astype(aubio.float_type)
  49         a_in[1] = 0
  50         a_in[3] = np.pi
  51         a_dct_in = a_dct(a_in)
  52         a_dct_reconstructed = a_dct.rdo(a_dct_in)
  53         assert_almost_equal(a_dct_reconstructed, a_in, decimal=6)
  54
  55     def test_negative_size(self):
  56         """ test that creation fails with a negative size """
  57         with self.assertRaises(ValueError):
  58             aubio.dct(-1)
  59
  60     def test_wrong_size(self):
  61         """ test that creation fails with a non power-of-two size """
  62         # supports for non 2** fft sizes only when compiled with fftw3
  63         size = 13
  64         try:
  65             with self.assertRaises(RuntimeError):
  66                 aubio.dct(size)
  67         except AssertionError:
  68             self.skipTest('creating aubio.dct with size %d did not fail' % size)