code: def testFullScaleSquare(self):
      # the vicker's loudness of a full scale square wave should
      # be 0dB, but it isn't (?)
      sr = 44100
      freq = 1000
      step = 0.5 * sr / freq
      size = 1 * sr
      val = 1
      square = zeros(size)
      for i in range(size):
          square[i] = val
          if i % step < 1.0:
              val *= -1
      result = 0
      nFrame = 0
      for frame in FrameGenerator(square):
          self.assertAlmostEqual(
              LoudnessVickers()(square), result, 0.15
          )
          nFrame += 1
  
file_path: essentia/test/src/unittests/temporal/test_loudnessvickers.py
imports: from essentia_test import *
label_desc: Use image node_id 6 for calling the TestLoudnessVickers obj's underlying member method code with example usage: obj.testFullScaleSquare() without return types