"""

from functools import reduce

import numpy as np

from warnings import warn

from . import xferfcn as tf

from . import statesp as ss

import numpy as np

from . import frdata as frd

from . import statesp as ss

from . import xferfcn as tf

from .iosys import InputOutputSystem

__all__ = ['series', 'parallel', 'negate', 'feedback', 'append', 'connect']

def series(sys1, *sysn):

def series(sys1, *sysn, **kwargs):

r"""series(sys1, sys2, [..., sysn])

Return the series connection (`sysn` \* ...\ \*) `sys2` \* `sys1`.

out : scalar, array, or :class:`InputOutputSystem`

Series interconnection of the systems.

Other Parameters

----------------

inputs, outputs : str, or list of str, optional

List of strings that name the individual signals. If not given,

signal names will be of the form `s[i]` (where `s` is one of `u`,

or `y`). See :class:`InputOutputSystem` for more information.

states : str, or list of str, optional

List of names for system states. If not given, state names will be

of of the form `x[i]` for interconnections of linear systems or

'<subsys_name>.<state_name>' for interconnected nonlinear systems.

name : string, optional

System name (used for specifying signals). If unspecified, a generic

name <sys[id]> is generated with a unique integer id.

Raises

------

ValueError

(2, 1, 5)

"""

return reduce(lambda x, y: y * x, sysn, sys1)

sys = reduce(lambda x, y: y * x, sysn, sys1)

sys.update_names(**kwargs)

return sys

def parallel(sys1, *sysn):

def parallel(sys1, *sysn, **kwargs):

r"""parallel(sys1, sys2, [..., sysn])

Return the parallel connection `sys1` + `sys2` (+ ...\ + `sysn`).

out : scalar, array, or :class:`InputOutputSystem`

Parallel interconnection of the systems.

Other Parameters

----------------

inputs, outputs : str, or list of str, optional

List of strings that name the individual signals. If not given,

signal names will be of the form `s[i]` (where `s` is one of `u`,

or `y`). See :class:`InputOutputSystem` for more information.

states : str, or list of str, optional

List of names for system states. If not given, state names will be

of of the form `x[i]` for interconnections of linear systems or

'<subsys_name>.<state_name>' for interconnected nonlinear systems.

name : string, optional

System name (used for specifying signals). If unspecified, a generic

name <sys[id]> is generated with a unique integer id.

Raises

------

ValueError

(3, 4, 7)

"""

return reduce(lambda x, y: x + y, sysn, sys1)

sys = reduce(lambda x, y: x + y, sysn, sys1)

sys.update_names(**kwargs)

return sys

def negate(sys):

def negate(sys, **kwargs):

"""

Return the negative of a system.

out : scalar, array, or :class:`InputOutputSystem`

Negated system.

Notes

-----

This function is a wrapper for the __neg__ function in the StateSpace and

TransferFunction classes. The output type is the same as the input type.

Other Parameters

----------------

inputs, outputs : str, or list of str, optional

List of strings that name the individual signals. If not given,

signal names will be of the form `s[i]` (where `s` is one of `u`,

or `y`). See :class:`InputOutputSystem` for more information.

states : str, or list of str, optional

List of names for system states. If not given, state names will be

of of the form `x[i]` for interconnections of linear systems or

'<subsys_name>.<state_name>' for interconnected nonlinear systems.

name : string, optional

System name (used for specifying signals). If unspecified, a generic

name <sys[id]> is generated with a unique integer id.

See Also

--------

append, feedback, interconnect, parallel, series

Notes

-----

This function is a wrapper for the __neg__ function in the StateSpace and

TransferFunction classes. The output type is the same as the input type.

Examples

--------

>>> G = ct.tf([2], [1, 1])

np.float64(-2.0)

"""

return -sys

sys = -sys

sys.update_names(**kwargs)

return sys

#! TODO: expand to allow sys2 default to work in MIMO case?

#! TODO: allow renaming of signals (for all bdalg operations)

def feedback(sys1, sys2=1, sign=-1):

def feedback(sys1, sys2=1, sign=-1, **kwargs):

"""Feedback interconnection between two I/O systems.

Parameters

out : scalar, array, or :class:`InputOutputSystem`

Feedback interconnection of the systems.

Other Parameters

----------------

inputs, outputs : str, or list of str, optional

List of strings that name the individual signals. If not given,

signal names will be of the form `s[i]` (where `s` is one of `u`,

or `y`). See :class:`InputOutputSystem` for more information.

states : str, or list of str, optional

List of names for system states. If not given, state names will be

of of the form `x[i]` for interconnections of linear systems or

'<subsys_name>.<state_name>' for interconnected nonlinear systems.

name : string, optional

System name (used for specifying signals). If unspecified, a generic

name <sys[id]> is generated with a unique integer id.

Raises

------

ValueError

# Allow anything with a feedback function to call that function

# TODO: rewrite to allow __rfeedback__

try:

return sys1.feedback(sys2, sign)

return sys1.feedback(sys2, sign, **kwargs)

except (AttributeError, TypeError):

pass

else:

sys1 = ss._convert_to_statespace(sys1)

return sys1.feedback(sys2, sign)

sys = sys1.feedback(sys2, sign)

sys.update_names(**kwargs)

return sys

def append(*sys):

def append(*sys, **kwargs):

"""append(sys1, sys2, [..., sysn])

Group LTI state space models by appending their inputs and outputs.

sys1, sys2, ..., sysn: scalar, array, or :class:`StateSpace`

I/O systems to combine.

Other Parameters

----------------

inputs, outputs : str, or list of str, optional

List of strings that name the individual signals. If not given,

signal names will be of the form `s[i]` (where `s` is one of `u`,

or `y`). See :class:`InputOutputSystem` for more information.

states : str, or list of str, optional

List of names for system states. If not given, state names will be

of of the form `x[i]` for interconnections of linear systems or

'<subsys_name>.<state_name>' for interconnected nonlinear systems.

name : string, optional

System name (used for specifying signals). If unspecified, a generic

name <sys[id]> is generated with a unique integer id.

Returns

-------

out: :class:`StateSpace`

s1 = ss._convert_to_statespace(sys[0])

for s in sys[1:]:

s1 = s1.append(s)

s1.update_names(**kwargs)

return s1

def connect(sys, Q, inputv, outputv):

--------

append, feedback, interconnect, negate, parallel, series

Notes

-----

The :func:`~control.interconnect` function in the :ref:`input/output

systems <iosys-module>` module allows the use of named signals and

provides an alternative method for interconnecting multiple systems.

Examples

--------

>>> G = ct.rss(7, inputs=2, outputs=2)

>>> T.ninputs, T.noutputs, T.nstates

(1, 2, 7)

Notes

-----

The :func:`~control.interconnect` function in the :ref:`input/output

systems <iosys-module>` module allows the use of named signals and

provides an alternative method for interconnecting multiple systems.

"""

# TODO: maintain `connect` for use in MATLAB submodule (?)

warn("`connect` is deprecated; use `interconnect`", DeprecationWarning)