tf = control.tf([[[-235, 1.146e4],    [-235, 1.146E4],    [-235, 1.146E4, 0]]],    [[[1, 48.78, 0],      [1, 48.78, 0, 0],      [0.008, 1.39, 48.78]]])tfOut[80]:Input 1 to output 1:-235 s + 1.146e+04------------------  s^2 + 48.78 sInput 2 to output 1:-235 s + 1.146e+04------------------  s^3 + 48.78 s^2Input 3 to output 1:  -235 s^2 + 1.146e+04 s--------------------------0.008 s^2 + 1.39 s + 48.78In [81]:​control.tf2ss(tf)---------------------------------------------------------------------------ImportError                               Traceback (most recent call last)/home/jgoppert/anaconda3/lib/python3.5/site-packages/control-dev-py3.5.egg/control/statesp.pyin _convertToStateSpace(sys,**kw)    646         try:--> 647             from slycot import td04ad    648if len(kw):ImportError: No module named'slycot'During handling of the above exception, another exception occurred:ValueError                                Traceback (most recent call last)<ipython-input-81-c8ef26438f31>in<module>()      1 ----> 2 control.tf2ss(tf)/home/jgoppert/anaconda3/lib/python3.5/site-packages/control-dev-py3.5.egg/control/statesp.pyin tf2ss(*args)   1082             raise TypeError("tf2ss(sys): sys must be a TransferFunction\   1083 object.")-> 1084return _convertToStateSpace(sys)   1085     else:   1086         raise ValueError("Needs 1 or 2 arguments; received %i." % len(args))/home/jgoppert/anaconda3/lib/python3.5/site-packages/control-dev-py3.5.egg/control/statesp.pyin _convertToStateSpace(sys,**kw)    671# I think this will fail if num and den aren't 1-D after    672# the squeeze--> 673             lti_sys = lti(squeeze(sys.num), squeeze(sys.den))    674return StateSpace(lti_sys.A, lti_sys.B, lti_sys.C, lti_sys.D,    675                               sys.dt)/home/jgoppert/anaconda3/lib/python3.5/site-packages/scipy/signal/ltisys.pyin __init__(self,*system,**kwargs)    759         self._den = None    760 --> 761         self.num, self.den = normalize(*system)    762     763     def __repr__(self):/home/jgoppert/anaconda3/lib/python3.5/site-packages/scipy/signal/filter_design.pyin normalize(b, a)   1084if len(b.shape) == 1:   1085         b = asarray([b], b.dtype.char)-> 1086while a[0] == 0.0 and len(a)> 1:   1087         a = a[1:]   1088     outb = b* (1.0) / a[0]ValueError: The truth value of an array with more than one element is ambiguous. Usea.any() ora.all()