docstr: Tests converting between unit interval and their frequencies in hertz.
docstr_tok: ["Tests","converting","between","unit","interval","and","their","frequencies","in","hertz","."]
code: def test_unit_to_hz_is_accurate(self):
      """Tests converting between unit interval and their frequencies in hertz."""
      hz_min = 20.0
      hz_max = 1000.0
      unit = np.linspace(0.0, 1.0, 128)
      np_hz = np.logspace(np.log10(hz_min), np.log10(hz_max), 128)
      tf_hz = core.unit_to_hz(unit, hz_min, hz_max)
      self.assertAllClose(np_hz, tf_hz)
  
imports: from absl.testing import parameterized
  from ddsp import core
  import librosa
  import numpy
  from scipy import signal
  import tensorflow.compat.v2
label_desc: Use image node_id 5 for calling the UtilitiesTest obj's underlying member method code with example usage: obj.test_unit_to_hz_is_accurate() without return types