Jun 29, 2024 · Jun 1, 2024 · Jun 1, 2024 · Jun 2, 2024 · Jun 4, 2024 · Jun 6, 2024
diff --git a/LICENSE b/LICENSE
 Copyright (c) 2009-2016 by California Institute of Technology
 Copyright (c) 2016-2023 by python-control developers
 Copyright (c) 2012 by Delft University of Technology
 Copyright (c) 2016-2024 by python-control developers
 All rights reserved.

 Redistribution and use in source and binary forms, with or without
diff --git a/control/__init__.py b/control/__init__.py
 from .timeplot import *

 from .bdalg import *
 from .ctrlplot import *
 from .delay import *
 from .descfcn import *
 from .dtime import *
diff --git a/control/bdalg.py b/control/bdalg.py
        if isinstance(sys2, (int, float, complex, np.number, np.ndarray,
                             tf.TransferFunction)):
            sys1 = tf._convert_to_transfer_function(sys1)
        elif isinstance(sys2, frd.FRD):
            sys1 = frd._convert_to_FRD(sys1, sys2.omega)
        elif isinstance(sys2, frd.FrequencyResponseData):
            sys1 = frd._convert_to_frd(sys1, sys2.omega)
        else:
            sys1 = ss._convert_to_statespace(sys1)

diff --git a/control/ctrlplot.py b/control/ctrlplot.py
 # ctrlplot.py - utility functions for plotting
 # Richard M. Murray, 14 Jun 2024
 #
 # Collection of functions that are used by various plotting functions.

 import matplotlib.pyplot as plt
 import numpy as np

 from . import config

 __all__ = ['suptitle']


 def suptitle(
        title, fig=None, frame='axes', **kwargs):
    """Add a centered title to a figure.

    This is a wrapper for the matplotlib `suptitle` function, but by
    setting ``frame`` to 'axes' (default) then the title is centered on the
    midpoint of the axes in the figure, rather than the center of the
    figure.  This usually looks better (particularly with multi-panel
    plots), though it takes longer to render.

    Parameters
    ----------
    title : str
        Title text.
    fig : Figure, optional
        Matplotlib figure.  Defaults to current figure.
    frame : str, optional
        Coordinate frame to use for centering: 'axes' (default) or 'figure'.
    **kwargs : :func:`matplotlib.pyplot.suptitle` keywords, optional
        Additional keywords (passed to matplotlib).

    """
    rcParams = config._get_param('freqplot', 'rcParams', kwargs, pop=True)

    if fig is None:
        fig = plt.gcf()

    if frame == 'figure':
        with plt.rc_context(rcParams):
            fig.suptitle(title, **kwargs)

    elif frame == 'axes':
        # TODO: move common plotting params to 'ctrlplot'
        rcParams = config._get_param('freqplot', 'rcParams', rcParams)
        with plt.rc_context(rcParams):
            plt.tight_layout()          # Put the figure into proper layout
            xc, _ = _find_axes_center(fig, fig.get_axes())

            fig.suptitle(title, x=xc, **kwargs)
            plt.tight_layout()          # Update the layout

    else:
        raise ValueError(f"unknown frame '{frame}'")


 def _find_axes_center(fig, axs):
    """Find the midpoint between axes in display coordinates.

    This function finds the middle of a plot as defined by a set of axes.

    """
    inv_transform = fig.transFigure.inverted()
    xlim = ylim = [1, 0]
    for ax in axs:
        ll = inv_transform.transform(ax.transAxes.transform((0, 0)))
        ur = inv_transform.transform(ax.transAxes.transform((1, 1)))

        xlim = [min(ll[0], xlim[0]), max(ur[0], xlim[1])]
        ylim = [min(ll[1], ylim[0]), max(ur[1], ylim[1])]

    return (np.sum(xlim)/2, np.sum(ylim)/2)
diff --git a/control/frdata.py b/control/frdata.py
 # Copyright (c) 2010 by California Institute of Technology
 # Copyright (c) 2012 by Delft University of Technology
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions
 # are met:
 #
 # 1. Redistributions of source code must retain the above copyright
 #    notice, this list of conditions and the following disclaimer.
 #
 # 2. Redistributions in binary form must reproduce the above copyright
 #    notice, this list of conditions and the following disclaimer in the
 #    documentation and/or other materials provided with the distribution.
 #
 # 3. Neither the names of the California Institute of Technology nor
 #    the Delft University of Technology nor
 #    the names of its contributors may be used to endorse or promote
 #    products derived from this software without specific prior
 #    written permission.
 #
 # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 # "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 # LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 # FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL CALTECH
 # OR THE CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 # SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 # LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 # USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 # ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 # OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 # OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 # SUCH DAMAGE.
 # frdata.py - frequency response data representation and functions
 #
 # Author: M.M. (Rene) van Paassen (using xferfcn.py as basis)
 # Date: 02 Oct 12


 """
 Frequency response data representation and functions.

 This module contains the FRD class and also functions that operate on
 FRD data.
 """

 # External function declarations
 from copy import copy
 from warnings import warn

 import numpy as np
 from numpy import angle, array, empty, ones, \
    real,imag, absolute, eye, linalg,where, sort
 from scipy.interpolate importsplprep, splev
 from numpy importabsolute,angle, array, empty, eye, imag, linalg, ones, \
    real,sort,where
 from scipy.interpolate importsplev, splprep

 from .lti importLTI, _process_frequency_response
 from . importconfig
 from .exception import pandas_check
 from .iosys import InputOutputSystem, _process_iosys_keywords, common_timebase
 from . importconfig
 from .lti importLTI, _process_frequency_response

 __all__ = ['FrequencyResponseData', 'FRD', 'frd']

    dt : float, True, or None
        System timebase.

    See Also
    --------
    frd

    Notes
    -----
    The main data members are 'omega' and 'fresp', where 'omega' is a 1D array
    for a more detailed description.

    """

    #
    # Class attributes
    #
                "Needs 1 or 2 arguments; received %i." % len(args))

        #
        # Processkey word arguments
        # Processkeyword arguments
        #

        # If data was generated by a system, keep track of that
        self.sysname = kwargs.pop('sysname', None)
        # If data was generated by a system, keep track of that (used when
        # plotting data).  Otherwise, use the system name, if given.
        self.sysname = kwargs.pop('sysname', kwargs.get('name', None))

        # Keep track of default properties for plotting
        self.plot_phase = kwargs.pop('plot_phase', None)
        """String representation of the transfer function."""

        mimo = self.ninputs > 1 or self.noutputs > 1
        outstr = ['Frequency response data']
        outstr = [f"{InputOutputSystem.__str__(self)}"]

        for i in range(self.ninputs):
            for j in range(self.noutputs):

        # Convert the second argument to a frequency response function.
        # or re-base the frd to the current omega (if needed)
        other =_convert_to_FRD(other, omega=self.omega)
        other =_convert_to_frd(other, omega=self.omega)

        # Check that the input-output sizes are consistent.
        if self.ninputs != other.ninputs:
            return FRD(self.fresp * other, self.omega,
                       smooth=(self.ifunc is not None))
        else:
            other =_convert_to_FRD(other, omega=self.omega)
            other =_convert_to_frd(other, omega=self.omega)

        # Check that the input-output sizes are consistent.
        if self.ninputs != other.noutputs:
            return FRD(self.fresp * other, self.omega,
                       smooth=(self.ifunc is not None))
        else:
            other =_convert_to_FRD(other, omega=self.omega)
            other =_convert_to_frd(other, omega=self.omega)

        # Check that the input-output sizes are consistent.
        if self.noutputs != other.ninputs:
            return FRD(self.fresp * (1/other), self.omega,
                       smooth=(self.ifunc is not None))
        else:
            other =_convert_to_FRD(other, omega=self.omega)
            other =_convert_to_frd(other, omega=self.omega)

        if (self.ninputs > 1 or self.noutputs > 1 or
            other.ninputs > 1 or other.noutputs > 1):
            return FRD(other / self.fresp, self.omega,
                       smooth=(self.ifunc is not None))
        else:
            other =_convert_to_FRD(other, omega=self.omega)
            other =_convert_to_frd(other, omega=self.omega)

        if (self.ninputs > 1 or self.noutputs > 1 or
            other.ninputs > 1 or other.noutputs > 1):
        ------
        ValueError
            If `s` is not purely imaginary, because
            :class:`FrequencyDomainData` systems are only defined at imaginary
 frequency values.
            :class:`FrequencyResponseData` systems are only defined at
 imaginary values (corresponding to real frequencies).

        """
        if s is None:
    def feedback(self, other=1, sign=-1):
        """Feedback interconnection between two FRD objects."""

        other =_convert_to_FRD(other, omega=self.omega)
        other =_convert_to_frd(other, omega=self.omega)

        if (self.noutputs != other.ninputs or self.ninputs != other.noutputs):
            raise ValueError(
 FRD = FrequencyResponseData


 def_convert_to_FRD(sys, omega, inputs=1, outputs=1):
 def_convert_to_frd(sys, omega, inputs=1, outputs=1):
    """Convert a system to frequency response data form (if needed).

    If sys is already an frd, and its frequency range matches or
    manually, as in:

    >>> import numpy as np
    >>> from control.frdata import_convert_to_FRD
    >>> from control.frdata import_convert_to_frd

    >>> omega = np.logspace(-1, 1)
    >>> frd =_convert_to_FRD(3., omega) # Assumes inputs = outputs = 1
    >>> frd =_convert_to_frd(3., omega) # Assumes inputs = outputs = 1
    >>> frd.ninputs, frd.noutputs
    (1, 1)

    >>> frd =_convert_to_FRD(1., omega, inputs=3, outputs=2)
    >>> frd =_convert_to_frd(1., omega, inputs=3, outputs=2)
    >>> frd.ninputs, frd.noutputs
    (3, 2)

                    sys.__class__)


 def frd(*args):
    """frd(d, w)

    Construct a frequency response data model.
 def frd(*args, **kwargs):
    """frd(response, omega[, dt])

 frd models store the (measured)frequency responseof a system.
 Construct afrequency responsedata (FRD) model.

    This function can be called in different ways:
    A frequency response data model stores the (measured) frequency response
    of a system.  This factory function can be called in different ways:

    ``frd(response,freqs)``
    ``frd(response,omega)``
        Create an frd model with the given response data, in the form of
        complex response vector, at matchingfrequency freqs [in rad/s]
        complex response vector, at matchingfrequencies ``omega`` [in rad/s].

    ``frd(sys,freqs)``
    ``frd(sys,omega)``
        Convert an LTI system into an frd model with data at frequencies
 freqs.
 ``omega``.

    Parameters
    ----------
    response: array_like, or list
        complex vector with the system response
    freq: array_lik or lis
        vector with frequencies
    sys: LTI (StateSpace or TransferFunction)
        A linear system
    response : array_like or LTI system
        Complex vector with the system response or an LTI system that can
        be used to copmute the frequency response at a list of frequencies.
    omega : array_like
        Vector of frequencies at which the response is evaluated.
    dt : float, True, or None
        System timebase.
    smooth : bool, optional
        If ``True``, create an interpolation function that allows the
        frequency response to be computed at any frequency within the range
        of frequencies give in ``omega``.  If ``False`` (default),
        frequency response can only be obtained at the frequencies
        specified in ``omega``.

    Returns
    -------
    sys: FRD
        New frequency response system
    sys : :class:`FrequencyResponseData`
        New frequency response data system.

    Other Parameters
    ----------------
    inputs, outputs : str, or list of str, optional
        List of strings that name the individual signals of the transformed
        system.  If not given, the inputs and outputs are the same as the
        original system.
    name : string, optional
        System name. If unspecified, a generic name <sys[id]> is generated
        with a unique integer id.

    See Also
    --------
 FRD, ss, tf
 FrequencyResponseData, frequency_response, ss, tf

    Examples
    --------
    >>> # Create from measurements
    >>> response = [1.0, 1.0, 0.5]
    >>>freqs = [1, 10, 100]
    >>> F = ct.frd(response,freqs)
    >>>omega = [1, 10, 100]
    >>> F = ct.frd(response,omega)

    >>> G = ct.tf([1], [1, 1])
    >>>freqs = [1, 10, 100]
    >>> F = ct.frd(G,freqs)
    >>>omega = [1, 10, 100]
    >>> F = ct.frd(G,omega)

    """
    returnFRD(*args)
    returnFrequencyResponseData(*args, **kwargs)
Original file line number	Diff line number	Diff line change
		@@ -1,5 +1,6 @@
		Copyright (c) 2009-2016 by California Institute of Technology
		Copyright (c) 2016-2023 by python-control developers
		Copyright (c) 2012 by Delft University of Technology
		Copyright (c) 2016-2024 by python-control developers
		All rights reserved.

		Redistribution and use in source and binary forms, with or without
Expand Down
Original file line number	Diff line number	Diff line change
Expand Up		@@ -83,6 +83,7 @@
		from .timeplot import *

		from .bdalg import *
		from .ctrlplot import *
		from .delay import *
		from .descfcn import *
		from .dtime import *
Expand Down
Original file line number	Diff line number	Diff line change
Expand Up		@@ -279,8 +279,8 @@ def feedback(sys1, sys2=1, sign=-1):
		if isinstance(sys2, (int, float, complex, np.number, np.ndarray,
		tf.TransferFunction)):
		sys1 = tf._convert_to_transfer_function(sys1)
		elif isinstance(sys2, frd.FRD):
		sys1 = frd._convert_to_FRD(sys1, sys2.omega)
		elif isinstance(sys2, frd.FrequencyResponseData):
		sys1 = frd._convert_to_frd(sys1, sys2.omega)
		else:
		sys1 = ss._convert_to_statespace(sys1)

Expand Down
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,74 @@
		# ctrlplot.py - utility functions for plotting
		# Richard M. Murray, 14 Jun 2024
		#
		# Collection of functions that are used by various plotting functions.

		import matplotlib.pyplot as plt
		import numpy as np

		from . import config

		__all__ = ['suptitle']


		def suptitle(
		title, fig=None, frame='axes', **kwargs):
		"""Add a centered title to a figure.

		This is a wrapper for the matplotlib `suptitle` function, but by
		setting ``frame`` to 'axes' (default) then the title is centered on the
		midpoint of the axes in the figure, rather than the center of the
		figure. This usually looks better (particularly with multi-panel
		plots), though it takes longer to render.

		Parameters
		----------
		title : str
		Title text.
		fig : Figure, optional
		Matplotlib figure. Defaults to current figure.
		frame : str, optional
		Coordinate frame to use for centering: 'axes' (default) or 'figure'.
		**kwargs : :func:`matplotlib.pyplot.suptitle` keywords, optional
		Additional keywords (passed to matplotlib).

		"""
		rcParams = config._get_param('freqplot', 'rcParams', kwargs, pop=True)

		if fig is None:
		fig = plt.gcf()

		if frame == 'figure':
		with plt.rc_context(rcParams):
		fig.suptitle(title, **kwargs)

		elif frame == 'axes':
		# TODO: move common plotting params to 'ctrlplot'
Copy link Member slivingstonJun 28, 2024 Choose a reason for hiding this comment The reason will be displayed to describe this comment to others.Learn more. This same TODO comment is already freqplot.py, and it is not clear what the comment means here (in ctrlplot). Should the TODO comment be deleted here in favor of the one in freqplot.py ? Copy link Member slivingstonJun 28, 2024 Choose a reason for hiding this comment The reason will be displayed to describe this comment to others.Learn more. Reading it again, I think this TODO comment is to be able to rcParams=config._get_param('ctrlplot','rcParams',rcParams) If so, then I understand the motivation, and OK to keep both TODO comments. Copy link MemberAuthor murrayrmJun 29, 2024 Choose a reason for hiding this comment The reason will be displayed to describe this comment to others.Learn more. I've got another PR coming that will address both TODOs. Doing things in stages so that everything is in (slightly) smaller chunks. Copy link Member slivingstonJun 29, 2024 Choose a reason for hiding this comment The reason will be displayed to describe this comment to others.Learn more. Awesome. I am almost done reviewing this one.
		rcParams = config._get_param('freqplot', 'rcParams', rcParams)
		with plt.rc_context(rcParams):
		plt.tight_layout() # Put the figure into proper layout
		xc, _ = _find_axes_center(fig, fig.get_axes())

		fig.suptitle(title, x=xc, **kwargs)
		plt.tight_layout() # Update the layout

		else:
		raise ValueError(f"unknown frame '{frame}'")


		def _find_axes_center(fig, axs):
		"""Find the midpoint between axes in display coordinates.

		This function finds the middle of a plot as defined by a set of axes.

		"""
		inv_transform = fig.transFigure.inverted()
		xlim = ylim = [1, 0]
		for ax in axs:
		ll = inv_transform.transform(ax.transAxes.transform((0, 0)))
		ur = inv_transform.transform(ax.transAxes.transform((1, 1)))

		xlim = [min(ll[0], xlim[0]), max(ur[0], xlim[1])]
		ylim = [min(ll[1], ylim[0]), max(ur[1], ylim[1])]

		return (np.sum(xlim)/2, np.sum(ylim)/2)
Original file line number	Diff line number	Diff line change
		@@ -1,61 +1,27 @@
		# Copyright (c) 2010 by California Institute of Technology
		# Copyright (c) 2012 by Delft University of Technology
		# All rights reserved.
		#
		# Redistribution and use in source and binary forms, with or without
		# modification, are permitted provided that the following conditions
		# are met:
		#
		# 1. Redistributions of source code must retain the above copyright
		# notice, this list of conditions and the following disclaimer.
		#
		# 2. Redistributions in binary form must reproduce the above copyright
		# notice, this list of conditions and the following disclaimer in the
		# documentation and/or other materials provided with the distribution.
		#
		# 3. Neither the names of the California Institute of Technology nor
		# the Delft University of Technology nor
		# the names of its contributors may be used to endorse or promote
		# products derived from this software without specific prior
		# written permission.
		#
		# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
		# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
		# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
		# FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL CALTECH
		# OR THE CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
		# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
		# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
		# USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
		# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
		# OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
		# OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
		# SUCH DAMAGE.
		# frdata.py - frequency response data representation and functions
		#
		# Author: M.M. (Rene) van Paassen (using xferfcn.py as basis)
		# Date: 02 Oct 12


		"""
		Frequency response data representation and functions.

		This module contains the FRD class and also functions that operate on
		FRD data.
		"""

		# External function declarations
		from copy import copy
		from warnings import warn

		import numpy as np
		from numpy import angle, array, empty, ones, \
		real,imag, absolute, eye, linalg,where, sort
		from scipy.interpolate importsplprep, splev
		from numpy importabsolute,angle, array, empty, eye, imag, linalg, ones, \
		real,sort,where
		from scipy.interpolate importsplev, splprep

		from .lti importLTI, _process_frequency_response
		from . importconfig
		from .exception import pandas_check
		from .iosys import InputOutputSystem, _process_iosys_keywords, common_timebase
		from . importconfig
		from .lti importLTI, _process_frequency_response

		__all__ = ['FrequencyResponseData', 'FRD', 'frd']

Expand DownExpand Up		@@ -100,6 +66,10 @@ class constructor, using the :func:~~control.frd` factory function
		dt : float, True, or None
		System timebase.

		See Also
		--------
		frd

		Notes
		-----
		The main data members are 'omega' and 'fresp', where 'omega' is a 1D array
Expand All		@@ -120,7 +90,6 @@ class constructor, using the :func:~~control.frd` factory function
		for a more detailed description.

		"""

		#
		# Class attributes
		#
Expand DownExpand Up		@@ -206,11 +175,12 @@ def __init__(self, args, *kwargs):
		"Needs 1 or 2 arguments; received %i." % len(args))

		#
		# Processkey word arguments
		# Processkeyword arguments
		#

		# If data was generated by a system, keep track of that
		self.sysname = kwargs.pop('sysname', None)
		# If data was generated by a system, keep track of that (used when
		# plotting data). Otherwise, use the system name, if given.
		self.sysname = kwargs.pop('sysname', kwargs.get('name', None))

		# Keep track of default properties for plotting
		self.plot_phase = kwargs.pop('plot_phase', None)
Expand DownExpand Up		@@ -280,7 +250,7 @@ def __str__(self):
		"""String representation of the transfer function."""

		mimo = self.ninputs > 1 or self.noutputs > 1
		outstr = ['Frequency response data']
		outstr = [f"{InputOutputSystem.__str__(self)}"]

		for i in range(self.ninputs):
		for j in range(self.noutputs):
Expand DownExpand Up		@@ -322,7 +292,7 @@ def __add__(self, other):

		# Convert the second argument to a frequency response function.
		# or re-base the frd to the current omega (if needed)
		other =_convert_to_FRD(other, omega=self.omega)
		other =_convert_to_frd(other, omega=self.omega)

		# Check that the input-output sizes are consistent.
		if self.ninputs != other.ninputs:
Expand DownExpand Up		@@ -359,7 +329,7 @@ def __mul__(self, other):
		return FRD(self.fresp * other, self.omega,
		smooth=(self.ifunc is not None))
		else:
		other =_convert_to_FRD(other, omega=self.omega)
		other =_convert_to_frd(other, omega=self.omega)

		# Check that the input-output sizes are consistent.
		if self.ninputs != other.noutputs:
Expand All		@@ -386,7 +356,7 @@ def __rmul__(self, other):
		return FRD(self.fresp * other, self.omega,
		smooth=(self.ifunc is not None))
		else:
		other =_convert_to_FRD(other, omega=self.omega)
		other =_convert_to_frd(other, omega=self.omega)

		# Check that the input-output sizes are consistent.
		if self.noutputs != other.ninputs:
Expand DownExpand Up		@@ -414,7 +384,7 @@ def __truediv__(self, other):
		return FRD(self.fresp * (1/other), self.omega,
		smooth=(self.ifunc is not None))
		else:
		other =_convert_to_FRD(other, omega=self.omega)
		other =_convert_to_frd(other, omega=self.omega)

		if (self.ninputs > 1 or self.noutputs > 1 or
		other.ninputs > 1 or other.noutputs > 1):
Expand All		@@ -433,7 +403,7 @@ def __rtruediv__(self, other):
		return FRD(other / self.fresp, self.omega,
		smooth=(self.ifunc is not None))
		else:
		other =_convert_to_FRD(other, omega=self.omega)
		other =_convert_to_frd(other, omega=self.omega)

		if (self.ninputs > 1 or self.noutputs > 1 or
		other.ninputs > 1 or other.noutputs > 1):
Expand DownExpand Up		@@ -572,8 +542,8 @@ def __call__(self, s=None, squeeze=None, return_magphase=None):
		------
		ValueError
		If `s` is not purely imaginary, because
		:class:`FrequencyDomainData` systems are only defined at imaginary
		frequency values.
		:class:`FrequencyResponseData` systems are only defined at
		imaginary values (corresponding to real frequencies).

		"""
		if s is None:
Expand DownExpand Up		@@ -638,7 +608,7 @@ def freqresp(self, omega):
		def feedback(self, other=1, sign=-1):
		"""Feedback interconnection between two FRD objects."""

		other =_convert_to_FRD(other, omega=self.omega)
		other =_convert_to_frd(other, omega=self.omega)

		if (self.noutputs != other.ninputs or self.ninputs != other.noutputs):
		raise ValueError(
Expand DownExpand Up		@@ -710,7 +680,7 @@ def to_pandas(self):
		FRD = FrequencyResponseData


		def_convert_to_FRD(sys, omega, inputs=1, outputs=1):
		def_convert_to_frd(sys, omega, inputs=1, outputs=1):
		"""Convert a system to frequency response data form (if needed).

		If sys is already an frd, and its frequency range matches or
Expand All		@@ -721,14 +691,14 @@ def _convert_to_FRD(sys, omega, inputs=1, outputs=1):
		manually, as in:

		>>> import numpy as np
		>>> from control.frdata import_convert_to_FRD
		>>> from control.frdata import_convert_to_frd

		>>> omega = np.logspace(-1, 1)
		>>> frd =_convert_to_FRD(3., omega) # Assumes inputs = outputs = 1
		>>> frd =_convert_to_frd(3., omega) # Assumes inputs = outputs = 1
		>>> frd.ninputs, frd.noutputs
		(1, 1)

		>>> frd =_convert_to_FRD(1., omega, inputs=3, outputs=2)
		>>> frd =_convert_to_frd(1., omega, inputs=3, outputs=2)
		>>> frd.ninputs, frd.noutputs
		(3, 2)

Expand DownExpand Up		@@ -777,51 +747,67 @@ def _convert_to_FRD(sys, omega, inputs=1, outputs=1):
		sys.__class__)


		def frd(*args):
		"""frd(d, w)

		Construct a frequency response data model.
		def frd(args, *kwargs):
		"""frd(response, omega[, dt])

		frd models store the (measured)frequency responseof a system.
		Construct afrequency responsedata (FRD) model.

		This function can be called in different ways:
		A frequency response data model stores the (measured) frequency response
		of a system. This factory function can be called in different ways:

		``frd(response,freqs)``
		``frd(response,omega)``
		Create an frd model with the given response data, in the form of
		complex response vector, at matchingfrequency freqs [in rad/s]
		complex response vector, at matchingfrequencies ``omega`` [in rad/s].

		``frd(sys,freqs)``
		``frd(sys,omega)``
		Convert an LTI system into an frd model with data at frequencies
		freqs.
		``omega``.

		Parameters
		----------
		response: array_like, or list
		complex vector with the system response
		freq: array_lik or lis
		vector with frequencies
		sys: LTI (StateSpace or TransferFunction)
		A linear system
		response : array_like or LTI system
		Complex vector with the system response or an LTI system that can
		be used to copmute the frequency response at a list of frequencies.
		omega : array_like
		Vector of frequencies at which the response is evaluated.
		dt : float, True, or None
		System timebase.
		smooth : bool, optional
		If ``True``, create an interpolation function that allows the
		frequency response to be computed at any frequency within the range
		of frequencies give in ``omega``. If ``False`` (default),
		frequency response can only be obtained at the frequencies
		specified in ``omega``.

		Returns
		-------
		sys: FRD
		New frequency response system
		sys : :class:`FrequencyResponseData`
		New frequency response data system.

		Other Parameters
		----------------
		inputs, outputs : str, or list of str, optional
		List of strings that name the individual signals of the transformed
		system. If not given, the inputs and outputs are the same as the
		original system.
		name : string, optional
		System name. If unspecified, a generic name <sys[id]> is generated
		with a unique integer id.

		See Also
		--------
		FRD, ss, tf
		FrequencyResponseData, frequency_response, ss, tf

		Examples
		--------
		>>> # Create from measurements
		>>> response = [1.0, 1.0, 0.5]
		>>>freqs = [1, 10, 100]
		>>> F = ct.frd(response,freqs)
		>>>omega = [1, 10, 100]
		>>> F = ct.frd(response,omega)

		>>> G = ct.tf([1], [1, 1])
		>>>freqs = [1, 10, 100]
		>>> F = ct.frd(G,freqs)
		>>>omega = [1, 10, 100]
		>>> F = ct.frd(G,omega)

		"""
		returnFRD(*args)
		returnFrequencyResponseData(args, *kwargs)