code: def testRegression(self):
      # with len(a) == len(b)
      ba = readVector(join(filedir(), "filters/ba.txt"))
      ab = readVector(join(filedir(), "filters/ab.txt"))
      signal = readVector(join(filedir(), "filters/x.txt"))
      expected = readVector(join(filedir(), "filters/y1.txt"))
  
      filt = IIR(numerator=ba, denominator=ab)
      self.assertAlmostEqualVector(filt(signal), expected, 1e-6)
  
      # with len(b) > len(a)
      b = readVector(join(filedir(), "filters/b.txt"))
      a = readVector(join(filedir(), "filters/a.txt"))
      expected = readVector(join(filedir(), "filters/y2.txt"))
  
      filt = IIR(numerator=b, denominator=a)
      self.assertAlmostEqualVector(filt(signal), expected, 1e-6)
  
      # with len(a) > len(b)
      expected = readVector(join(filedir(), "filters/y3.txt"))
  
      filt = IIR(numerator=a, denominator=b)
      self.assertAlmostEqualVector(filt(signal), expected, 1e-6)
  
file_path: essentia/test/src/unittests/filters/test_iir.py
imports: from essentia_test import *
label_desc: Use image node_id 6 for calling the TestIIR obj's underlying member method code with example usage: obj.testRegression() without return types