LaTeX printout of transfer function ignores imaginary part without warning #719

In [13]: H_goertzel = (1-np.exp(-2j*pi*k/N)*z**-1)/(1 -2*np.cos(2*pi*k/N)*z**-1+z**-2)

In [14]: H_goertzel
Out[14]: 

In [15]: H_goertzel.num
Out[15]: 
[[array([ 1.        +0.j        , -0.30901699+0.95105652j,
          0.        +0.j        ,  0.        +0.j        ,
          0.        +0.j        ])]]
In [16]: H_goertzel.den
Out[16]: [[array([ 1.        , -0.61803399,  1.        ,  0.        ,  0.        ])]]