control.sample_system

control.sample_system(sysc, Ts, method='zoh', alpha=None, prewarp_frequency=None, name=None, copy_names=True, **kwargs)[source]

Convert a continuous-time system to discrete time by sampling.

Parameters

syscStateSpace or TransferFunction: Continuous time system to be converted.
Tsfloat > 0: Sampling period.
methodstring: Method to use for conversion, e.g. ‘bilinear’, ‘zoh’ (default).
alphafloat within [0, 1]: The generalized bilinear transformation weighting parameter, which should only be specified with method=”gbt”, and is ignored otherwise. See scipy.signal.cont2discrete.
prewarp_frequencyfloat within [0, infinity): The frequency [rad/s] at which to match with the input continuous- time system’s magnitude and phase (only valid for method=’bilinear’, ‘tustin’, or ‘gbt’ with alpha=0.5).

Returns

sysdLTI of the same class (StateSpace or TransferFunction): Discrete time system, with sampling rate Ts.

Other Parameters

inputsint, list of str or None, optional: Description of the system inputs. If not specified, the original system inputs are used. See InputOutputSystem for more information.
outputsint, list of str or None, optional: Description of the system outputs. Same format as inputs.
statesint, list of str, or None, optional: Description of the system states. Same format as inputs. Only available if the system is StateSpace.
namestring, optional: Set the name of the sampled system. If not specified and if copy_names is False, a generic name ‘sys[id]’ is generated with a unique integer id. If copy_names is True, the new system name is determined by adding the prefix and suffix strings in config.defaults['iosys.sampled_system_name_prefix'] and config.defaults['iosys.sampled_system_name_suffix'], with the default being to add the suffix ‘$sampled’.
copy_namesbool, optional: If True, copy the names of the input signals, output signals, and states to the sampled system.

Notes

See StateSpace.sample or TransferFunction.sample for further details on implementation for state space and transfer function systems, including available methods.

Examples

>>> Gc = ct.tf([1], [1, 2, 1])
>>> Gc.isdtime()
False
>>> Gd = ct.sample_system(Gc, 1, method='bilinear')
>>> Gd.isdtime()
True