from aubio import zero_crossing_rate

#! /usr/bin/env python

from numpy.testing import TestCase

buf_size = 2048
channels = 1

class zero_crossing_rate_test_case(TestCase):

  def setUp(self):
    self.vector = new_fvec(buf_size, channels)

  def tearDown(self):
    del_fvec(self.vector)

  def test(self):
    """ create and delete fvec """
    pass

  def test_zeroes(self):
    """ check zero crossing rate on a buffer of 0. """
    self.assertEqual(0., zero_crossing_rate(self.vector))

  def test_ones(self):
    """ check zero crossing rate on a buffer of 1. """
    for index in range(buf_size):
      for channel in range(channels):
        fvec_write_sample(self.vector, 1., channel, index)
    self.assertEqual(0., zero_crossing_rate(self.vector))

  def test_impulse(self):
    """ check zero crossing rate on a buffer with an impulse """
    fvec_write_sample(self.vector, 1., 0, buf_size / 2)
    self.assertEqual(0., zero_crossing_rate(self.vector))

  def test_negative_impulse(self):
    """ check zero crossing rate on a buffer with a negative impulse """
    fvec_write_sample(self.vector, -1., 0, buf_size / 2)
    self.assertEqual(2./buf_size, zero_crossing_rate(self.vector))

  def test_single(self):
    """ check zero crossing rate on single crossing """
    fvec_write_sample(self.vector, +1., 0, buf_size / 2 - 1)
    fvec_write_sample(self.vector, -1., 0, buf_size / 2)
    self.assertEqual(2./buf_size, zero_crossing_rate(self.vector))

  def test_single_with_gap(self):
    """ check zero crossing rate on single crossing with a gap"""
    fvec_write_sample(self.vector, +1., 0, buf_size / 2 - 2)
    fvec_write_sample(self.vector, -1., 0, buf_size / 2)
    self.assertEqual(2./buf_size, zero_crossing_rate(self.vector))

if __name__ == '__main__':
  unittest.main()