Expand Up @@ -59,7 +59,8 @@ from numpy.linalg import solve, eigvals, matrix_rank from numpy.linalg.linalg import LinAlgError import scipy as sp from scipy.signal import lti, cont2discrete from scipy.signal import cont2discrete from scipy.signal import StateSpace as signalStateSpace from warnings import warn from .lti import LTI, timebase, timebaseEqual, isdtime from . import config Expand Down Expand Up @@ -200,7 +201,7 @@ def __init__(self, *args, **kw): raise ValueError("Needs 1 or 4 arguments; received %i." % len(args))
# Process keyword arguments remove_useless = kw.get('remove_useless', remove_useless = kw.get('remove_useless', config.defaults['statesp.remove_useless_states'])
# Convert all matrices to standard form Expand Down Expand Up @@ -798,9 +799,7 @@ def minreal(self, tol=0.0): else: return StateSpace(self)

# TODO: add discrete time check def returnScipySignalLTI(self): def returnScipySignalLTI(self, strict=True): """Return a list of a list of :class:`scipy.signal.lti` objects.
For instance, Expand All @@ -809,15 +808,45 @@ def returnScipySignalLTI(self): >>> out[3][5]
is a :class:`scipy.signal.lti` object corresponding to the transfer function from the 6th input to the 4th output.""" function from the 6th input to the 4th output.
Parameters ---------- strict : bool, optional True (default): The timebase `ssobject.dt` cannot be None; it must be continuous (0) or discrete (True or > 0). False: If `ssobject.dt` is None, continuous time :class:`scipy.signal.lti` objects are returned.
Returns ------- out : list of list of :class:`scipy.signal.StateSpace` continuous time (inheriting from :class:`scipy.signal.lti`) or discrete time (inheriting from :class:`scipy.signal.dlti`) SISO objects """ if strict and self.dt is None: raise ValueError("with strict=True, dt cannot be None")
if self.dt: kwdt = {'dt': self.dt} else: # scipy convention for continuous time lti systems: call without # dt keyword argument kwdt = {}
# Preallocate the output. out = [[[] for _ in range(self.inputs)] for _ in range(self.outputs)]
for i in range(self.outputs): for j in range(self.inputs): out[i][j] = lti(asarray(self.A), asarray(self.B[:, j]), asarray(self.C[i, :]), self.D[i, j]) out[i][j] = signalStateSpace(asarray(self.A), asarray(self.B[:, j:j + 1]), asarray(self.C[i:i + 1, :]), asarray(self.D[i:i + 1, j:j + 1]), **kwdt)
return out
Expand Down