code: def test_hztomel(self):
      assert_equal(hztomel(0.0), 0.0)
      assert_almost_equal(hztomel(400.0 / 3.0), 2.0, decimal=5)
      assert_almost_equal(hztomel(1000.0 / 3), 5.0)
      # on 32bit, some of these tests fails unless compiling with -ffloat-store
      try:
          assert_equal(hztomel(200.0), 3.0)
      except AssertionError:
          if not is32bit():
              raise
          assert_almost_equal(hztomel(200.0), 3.0, decimal=5)
      assert_almost_equal(hztomel(1000.0), 15)
      assert_almost_equal(hztomel(6400), 42, decimal=5)
      assert_almost_equal(hztomel(40960), 69, decimal=5)
  
      for m in np.linspace(0, 1000, 100):
          assert_almost_equal(hztomel(meltohz(m)) - m, 0, decimal=3)
  
imports: from unittest import main
  from numpy.testing import TestCase
  from numpy.testing import assert_equal, assert_almost_equal
  from _tools import assert_warns
  from utils import is32bit
  import numpy
  import aubio
  from aubio import hztomel, meltohz
  from aubio import hztomel_htk, meltohz_htk
label_desc: Use image node_id 1 for calling the aubio_hztomel_test_case obj's underlying member method code with example usage: obj.test_hztomel() without return types