#NEWLINE# def mod1( ) : #NEWLINE# #INDENT# 'A description of the first-order modulator.\n\n    **Returns:**\n\n    ABCD, NTF, STF : a tuple of (ndarray, lti, lti)\n        The elements are the ABCD matrix (ndarray), the NTF (LTI object), the\n        STF (LTI object).\n\n    .. note::\n\n        If a version of the ``scipy`` library equal to 0.16.x or greater is in\n        use, the NTF and STF objects will be ``ZeroPolesGain`` objects, a\n        subclass of the scipy LTI object (``scipy.signal.lti``).\n\n    ' #NEWLINE# A = np . array ( [ [ 1.0 ] ] ) #NEWLINE# B = np . array ( [ [ 1.0 , ( - 1.0 ) ] ] ) #NEWLINE# C = np . array ( [ [ 1.0 ] ] ) #NEWLINE# D = np . array ( [ [ 0.0 , 0.0 ] ] ) #NEWLINE# ABCD = np . vstack ( ( np . hstack ( ( A , B ) ) , np . hstack ( ( C , D ) ) ) ) #NEWLINE# ( H , G ) = calculateTF ( ABCD ) #NEWLINE# return ( ABCD , H , D )