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 class aubio_dct(TestCase):
   9
  10     def test_init(self):
  11         """ check aubio.dct() can be created """
  12         a_dct = aubio.dct()
  13         self.assertEqual(a_dct.size, 1024)
  14
  15     def test_arange(self):
  16         """ test that dct(arange(8)) is computed correctly
  17
  18         >>> from scipy.fftpack import dct
  19         >>> a_in = np.arange(8).astype('float32')
  20         >>> precomputed = dct(a_in, norm='ortho')
  21         """
  22         precomputed = [ 9.89949512, -6.44232273,  0., -0.67345482, 0.,
  23                 -0.20090288, 0., -0.05070186]
  24         a_dct = aubio.dct(8)
  25         a_in = np.arange(8).astype('float32')
  26         a_expected = aubio.fvec(precomputed)
  27         assert_almost_equal(a_dct(a_in), a_expected, decimal=6)
  28
  29     def test_some_ones(self):
  30         """ test that dct(somevector) is computed correctly """
  31         precomputed = [ 4.28539848,  0.2469689,  -0.14625292, -0.58121818,
  32                 -0.83483052, -0.75921834, -0.35168475,  0.24087936,
  33                 0.78539824, 1.06532764,  0.97632152,  0.57164496, 0.03688532,
  34                 -0.39446154, -0.54619485, -0.37771079]
  35         a_dct = aubio.dct(16)
  36         a_in = np.ones(16).astype('float32')
  37         a_in[1] = 0
  38         a_in[3] = np.pi
  39         a_expected = aubio.fvec(precomputed)
  40         assert_almost_equal(a_dct(a_in), a_expected, decimal=7)
  41
  42     def test_reconstruction(self):
  43         a_dct = aubio.dct(16)
  44         a_in = np.ones(16).astype('float32')
  45         a_in[1] = 0
  46         a_in[3] = np.pi
  47         a_dct_in = a_dct(a_in)
  48         a_dct_reconstructed = a_dct.rdo(a_dct_in)
  49         assert_almost_equal(a_dct_reconstructed, a_in, decimal=6)
  50
  51     def test_negative_size(self):
  52         with self.assertRaises(ValueError):
  53             aubio.dct(-1)
  54
  55     def test_wrong_size(self):
  56         # supports for non 2** fft sizes only when compiled with fftw3
  57         try:
  58             with self.assertRaises(RuntimeError):
  59                 aubio.dct(13)
  60         except AssertionError:
  61             self.skipTest('creating aubio.dct with size %d did not fail' % win_s)