accuracies. If (numerator, denominator) is passed in for ``*system``, coefficients for both the numerator and denominator should be specified in descending exponent order (e.g., ``z^2 + 3z + 5`` would be represented as ``[1, 3, 5]``). Examples -------- Construct the transfer function :math:`H(z) = \frac{z^2 + 3z + 3}{z^2 + 2z + 1}` with a sampling time of 0.5 seconds: >>> from scipy import signal >>> num = [1, 3, 3] >>> den = [1, 2, 1] >>> signal.TransferFunction(num, den, dt=0.5) TransferFunctionDiscrete( array([ 1., 3., 3.]), array([ 1., 2., 1.]), dt: 0.5 ) r”