code: def create_sine(hop_s, freq, samplerate):
      t = np.arange(hop_s).astype(float_type)
      return np.sin(2.0 * np.pi * freq * t / float(samplerate))
  
imports: from numpy.testing import TestCase, assert_equal, assert_array_less
  from _tools import parametrize, skipTest
  from aubio import fvec, cvec, pvoc, float_type
  import numpy
label_desc: Use image node_id 1 for calling a global function with example usage: create_sine(hop_s, freq, samplerate) and returns: np