assertEquals("Instance " + (i + 1), Math.log(inst.value(1)/5), inst.value(inst.numAttributes() - 1), EXPR_DELTA);
if (inst.value(1) != 0) { assertEquals("Instance " + (i + 1), Math.log(inst.value(1)/5), inst.value(inst.numAttributes() - 1), EXPR_DELTA); }
  public void testLog() {    m_Filter = getFilter("log(a2/5)");    Instances result = useFilter();    for (int i = 0; i < result.numInstances(); i++) {      Instance inst = result.instance(i);      assertEquals("Instance " + (i + 1),                   Math.log(inst.value(1)/5),                    inst.value(inst.numAttributes() - 1), EXPR_DELTA);    }  }