Apr 27, 2023 · Apr 27, 2023
diff --git a/control/statesp.py b/control/statesp.py
        fpeak /= sys.dt

    return gpeak, fpeak

 def discrete2cont(sys, method='zoh'):
    """ Transform a discrete state-space system to a continuous state-space system.
    Parameters
 ------
 sys : Discrete LTI (StateSpace or TransferFunction) system to transform
 method: The method that was used for discretization

 Returns
 ------
 sysc : Continuous LIT (StateSpace or TransferFunction) system depending on the input form.
    """
    # check if system is of type state space and convert if not
    #if sys.

    if not(isinstance(sys, StateSpace)):
    sys = convert_to_statespace(sys)
    was_tf = true
    if method == 'zoh':
        Ac = scipy.linalg.logm(sys.A)/sys.dt
        Bc = np.linalg.inv(np.linalg.inv(Ac)@(sys.A-np.eye(np.shape(sys.A)[0])))@sys.B

        # remove small  numbers
        Ac = np.around(Ac/1e-6)*1e-6
        Bc = np.around(Bc/1e-6)*1e-6

        # turn -0 to 0
        Ac[np.abs(Ac)<1e-6] = 0
        Bc[np.abs(Bc)<1e-6] = 0

        sysc = StateSpace(Ac,Bc,sys.C,sys.D,0)
    else:
        raise NotImplementedError("Method: " + method + " is not implemented in this function!")

    if was_tf:
        sysc = ss2tf(sysc)

    return sysc
Original file line number	Diff line number	Diff line change
Expand Up		@@ -1988,3 +1988,41 @@ def linfnorm(sys, tol=1e-10):
		fpeak /= sys.dt

		return gpeak, fpeak

		def discrete2cont(sys, method='zoh'):
		""" Transform a discrete state-space system to a continuous state-space system.
		Parameters
		------
		sys : Discrete LTI (StateSpace or TransferFunction) system to transform
		method: The method that was used for discretization

		Returns
		------
		sysc : Continuous LIT (StateSpace or TransferFunction) system depending on the input form.
		"""
		# check if system is of type state space and convert if not
		#if sys.

		if not(isinstance(sys, StateSpace)):
		sys = convert_to_statespace(sys)
		was_tf = true
		if method == 'zoh':
		Ac = scipy.linalg.logm(sys.A)/sys.dt
		Bc = np.linalg.inv(np.linalg.inv(Ac)@(sys.A-np.eye(np.shape(sys.A)[0])))@sys.B

		# remove small numbers
		Ac = np.around(Ac/1e-6)*1e-6
		Bc = np.around(Bc/1e-6)*1e-6

		# turn -0 to 0
		Ac[np.abs(Ac)<1e-6] = 0
		Bc[np.abs(Bc)<1e-6] = 0

		sysc = StateSpace(Ac,Bc,sys.C,sys.D,0)
		else:
		raise NotImplementedError("Method: " + method + " is not implemented in this function!")

		if was_tf:
		sysc = ss2tf(sysc)

		return sysc