python-control · murrayrm · Jul 7, 2024 · Jun 4, 2024 · Jun 16, 2024 · Jun 16, 2024
diff --git a/control/ctrlplot.py b/control/ctrlplot.py
@@ -3,12 +3,14 @@
 #
 # Collection of functions that are used by various plotting functions.
 
+from os.path import commonprefix
+
 import matplotlib.pyplot as plt
 import numpy as np
 
 from . import config
 
-__all__ = ['suptitle']
+__all__ = ['suptitle', 'get_plot_axes']
 
 
 def suptitle(
@@ -44,7 +46,6 @@ def suptitle(
 
     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())
@@ -56,6 +57,93 @@ def suptitle(
         raise ValueError(f"unknown frame '{frame}'")
 
 
+# Create vectorized function to find axes from lines
+def get_plot_axes(line_array):
+    """Get a list of axes from an array of lines.
+
+    This function can be used to return the set of axes corresponding to
+    the line array that is returned by `time_response_plot`.  This is useful for
+    generating an axes array that can be passed to subsequent plotting
+    calls.
+
+    Parameters
+    ----------
+    line_array : array of list of Line2D
+        A 2D array with elements corresponding to a list of lines appearing
+        in an axes, matching the return type of a time response data plot.
+
+    Returns
+    -------
+    axes_array : array of list of Axes
+        A 2D array with elements corresponding to the Axes assocated with
+        the lines in `line_array`.
+
+    Notes
+    -----
+    Only the first element of each array entry is used to determine the axes.
+
+    """
+    _get_axes = np.vectorize(lambda lines: lines[0].axes)
+    return _get_axes(line_array)
+
+#
+# Utility functions
+#
+
+
+# Utility function to make legend labels
+def _make_legend_labels(labels, ignore_common=False):
+
+    # Look for a common prefix (up to a space)
+    common_prefix = commonprefix(labels)
+    last_space = common_prefix.rfind(', ')
+    if last_space < 0 or ignore_common:
+        common_prefix = ''
+    elif last_space > 0:
+        common_prefix = common_prefix[:last_space]
+    prefix_len = len(common_prefix)
+
+    # Look for a common suffix (up to a space)
+    common_suffix = commonprefix(
+        [label[::-1] for label in labels])[::-1]
+    suffix_len = len(common_suffix)
+    # Only chop things off after a comma or space
+    while suffix_len > 0 and common_suffix[-suffix_len] != ',':
+        suffix_len -= 1
+
+    # Strip the labels of common information
+    if suffix_len > 0 and not ignore_common:
+        labels = [label[prefix_len:-suffix_len] for label in labels]
+    else:
+        labels = [label[prefix_len:] for label in labels]
+
+    return labels
+
+
+def _update_suptitle(fig, title, rcParams=None, frame='axes'):
+    if fig is not None and isinstance(title, str):
+        # Get the current title, if it exists
+        old_title = None if fig._suptitle is None else fig._suptitle._text
+
+        if old_title is not None:
+            # Find the common part of the titles
+            common_prefix = commonprefix([old_title, title])
+
+            # Back up to the last space
+            last_space = common_prefix.rfind(' ')
+            if last_space > 0:
+                common_prefix = common_prefix[:last_space]
+            common_len = len(common_prefix)
+
+            # Add the new part of the title (usually the system name)
+            if old_title[common_len:] != title[common_len:]:
+                separator = ',' if len(common_prefix) > 0 else ';'
+                title = old_title + separator + title[common_len:]
+
+        # Add the title
+        suptitle(title, fig=fig, rcParams=rcParams, frame=frame)
+
+
 def _find_axes_center(fig, axs):
     """Find the midpoint between axes in display coordinates.
 

diff --git a/control/frdata.py b/control/frdata.py
@@ -653,6 +653,14 @@ def plot(self, plot_type=None, *args, **kwargs):
 
     # Convert to pandas
     def to_pandas(self):
+        """Convert response data to pandas data frame.
+
+        Creates a pandas data frame for the value of the frequency
+        response at each `omega`.  The frequency response values are
+        labeled in the form "H_{<out>, <in>}" where "<out>" and "<in>"
+        are replaced with the output and input labels for the system.
+
+        """
         if not pandas_check():
             ImportError('pandas not installed')
         import pandas

diff --git a/control/freqplot.py b/control/freqplot.py
@@ -19,14 +19,14 @@
 
 from . import config
 from .bdalg import feedback
-from .ctrlplot import suptitle, _find_axes_center
+from .ctrlplot import suptitle, _find_axes_center, _make_legend_labels, \
+    _update_suptitle
 from .ctrlutil import unwrap
 from .exception import ControlMIMONotImplemented
 from .frdata import FrequencyResponseData
 from .lti import LTI, _process_frequency_response, frequency_response
 from .margins import stability_margins
 from .statesp import StateSpace
-from .timeplot import _make_legend_labels
 from .xferfcn import TransferFunction
 
 __all__ = ['bode_plot', 'NyquistResponseData', 'nyquist_response',
@@ -954,28 +954,7 @@ def gen_zero_centered_series(val_min, val_max, period):
         else:
             title = data[0].title
 
-    if fig is not None and isinstance(title, str):
-        # Get the current title, if it exists
-        old_title = None if fig._suptitle is None else fig._suptitle._text
-        new_title = title
-
-        if old_title is not None:
-            # Find the common part of the titles
-            common_prefix = commonprefix([old_title, new_title])
-
-            # Back up to the last space
-            last_space = common_prefix.rfind(' ')
-            if last_space > 0:
-                common_prefix = common_prefix[:last_space]
-            common_len = len(common_prefix)
-
-            # Add the new part of the title (usually the system name)
-            if old_title[common_len:] != new_title[common_len:]:
-                separator = ',' if len(common_prefix) > 0 else ';'
-                new_title = old_title + separator + new_title[common_len:]
-
-        # Add the title
-        suptitle(title, fig=fig, rcParams=rcParams, frame=suptitle_frame)
+    _update_suptitle(fig, title, rcParams=rcParams, frame=suptitle_frame)
 
     #
     # Create legends
@@ -2668,12 +2647,13 @@ def _get_line_labels(ax, use_color=True):
 
 
 # Turn label keyword into array indexed by trace, output, input
-def _process_line_labels(label, nsys, ninputs=0, noutputs=0):
+# TODO: move to ctrlutil.py and update parameter names to reflect general use
+def _process_line_labels(label, ntraces, ninputs=0, noutputs=0):
     if label is None:
         return None
 
     if isinstance(label, str):
-        label = [label]
+        label = [label] * ntraces          # single label for all traces
 
     # Convert to an ndarray, if not done aleady
     try:
@@ -2685,12 +2665,14 @@ def _process_line_labels(label, nsys, ninputs=0, noutputs=0):
     # TODO: allow more sophisticated broadcasting (and error checking)
     try:
         if ninputs > 0 and noutputs > 0:
-            if line_labels.ndim == 1:
-                line_labels = line_labels.reshape(nsys, 1, 1)
-            line_labels = np.broadcast_to(
-                line_labels,(nsys, ninputs, noutputs))
+            if line_labels.ndim == 1 and line_labels.size == ntraces:
+                line_labels = line_labels.reshape(ntraces, 1, 1)
+                line_labels = np.broadcast_to(
+                    line_labels, (ntraces, ninputs, noutputs))
+            else:
+                line_labels = line_labels.reshape(ntraces, ninputs, noutputs)
     except:
-        if line_labels.shape[0] != nsys:
+        if line_labels.shape[0] != ntraces:
             raise ValueError("number of labels must match number of traces")
         else:
             raise ValueError("labels must be given for each input/output pair")

diff --git a/control/nlsys.py b/control/nlsys.py
@@ -27,8 +27,8 @@
 from . import config
 from .iosys import InputOutputSystem, _parse_spec, _process_iosys_keywords, \
     _process_signal_list, common_timebase, isctime, isdtime
-from .timeresp import TimeResponseData, _check_convert_array, \
-    _process_time_response
+from .timeresp import _check_convert_array, _process_time_response, \
+    TimeResponseData, TimeResponseList
 
 __all__ = ['NonlinearIOSystem', 'InterconnectedSystem', 'nlsys',
            'input_output_response', 'find_eqpt', 'linearize',
@@ -1327,8 +1327,8 @@ def input_output_response(
 
     Parameters
     ----------
-    sys : InputOutputSystem
-        Input/output system to simulate.
+    sys : NonlinearIOSystem or list of NonlinearIOSystem
+        I/O system(s) for which input/output response is simulated.
 
     T : array-like
         Time steps at which the input is defined; values must be evenly spaced.
@@ -1448,6 +1448,16 @@ def input_output_response(
     if kwargs:
         raise TypeError("unrecognized keyword(s): ", str(kwargs))
 
+    # If passed a list, recursively call individual responses with given T
+    if isinstance(sys, (list, tuple)):
+        sysdata, responses = sys, []
+        for sys in sysdata:
+            responses.append(input_output_response(
+                sys, T, U=U, X0=X0, params=params, transpose=transpose,
+                return_x=return_x, squeeze=squeeze, t_eval=t_eval,
+                solve_ivp_kwargs=solve_ivp_kwargs, **kwargs))
+        return TimeResponseList(responses)
+
     # Sanity checking on the input
     if not isinstance(sys, NonlinearIOSystem):
         raise TypeError("System of type ", type(sys), " not valid")

diff --git a/control/tests/kwargs_test.py b/control/tests/kwargs_test.py
@@ -308,6 +308,7 @@ def test_response_plot_kwargs(data_fcn, plot_fcn, mimo):
     'StateSpace.sample': test_unrecognized_kwargs,
     'TimeResponseData.__call__': trdata_test.test_response_copy,
     'TimeResponseData.plot': timeplot_test.test_errors,
+    'TimeResponseList.plot': timeplot_test.test_errors,
     'TransferFunction.__init__': test_unrecognized_kwargs,
     'TransferFunction.sample': test_unrecognized_kwargs,
     'optimal.OptimalControlProblem.__init__':