control.tf2ss

control.tf2ss(sys)

Transform a transfer function to a state space system.

The function accepts either 1 or 2 parameters:

tf2ss(sys)
Convert a linear system into transfer function form. Always creates a new system, even if sys is already a TransferFunction object.
tf2ss(num, den)

Create a transfer function system from its numerator and denominator polynomial coefficients.

For details see: tf()

Parameters:
  • sys (LTI (StateSpace or TransferFunction)) – A linear system
  • num (array_like, or list of list of array_like) – Polynomial coefficients of the numerator
  • den (array_like, or list of list of array_like) – Polynomial coefficients of the denominator
Returns:

out – New linear system in state space form

Return type:

StateSpace

Raises:
  • ValueError – if num and den have invalid or unequal dimensions, or if an invalid number of arguments is passed in
  • TypeError – if num or den are of incorrect type, or if sys is not a TransferFunction object

See also

ss(), tf(), ss2tf()

Examples

>>> num = [[[1., 2.], [3., 4.]], [[5., 6.], [7., 8.]]]
>>> den = [[[9., 8., 7.], [6., 5., 4.]], [[3., 2., 1.], [-1., -2., -3.]]]
>>> sys1 = tf2ss(num, den)
>>> sys_tf = tf(num, den)
>>> sys2 = tf2ss(sys_tf)