dysys.transferfunctionsymbolic

Module Contents

Classes

TransferFunctionSymbolic

Represents a SISO continuous LTI transfer function model in symbolic form

Functions

tfs(H[, s])

Create a TransferFunctionSymbolic object

Attributes

s

class dysys.transferfunctionsymbolic.TransferFunctionSymbolic(H, s=None)

Represents a SISO continuous LTI transfer function model in symbolic form

__call__(s)

Evaluate the transfer function at a complex frequency s

__str__()

Return str(self).

__factor_p(p, poles=True)
factor()

Returns an overall gain and a list of standard-form terms

__num_den_lists(params={})

Returns num and den coefficients as lists

Parameters:

params (dict) –

to_control(params={})

Returns an equivalent Control Systems package control.TransferFunction object

Parameters:

params (dict) –

poles()

Returns a dict of the symbolic poles as keys and multiplicity as values

zeros()

Returns a dict of the symbolic zeros as keys and multiplicity as values

dc_gain()

Returns the DC gain of the transfer function

frequency_response_function(w=sp.symbols('w', real=True))

Returns the symbolic frequency response function (FRF)

Evaluates H(jw). Assumes the region of convergence for the corresponding Fourier transform is congruent with that of the Laplace transform.

Parameters:

w (sympy.Symbol) – The frequency symbol

forced_response(t, u=None, U=None, laplace=False)

Returns the forced response of a SISO system

The inverse Laplace transform is used to compute the forced response. Exactly one of arguments u or U may be provided.

Parameters:
  • t (sympy.Symbol) – The time symbol

  • u (sympy.Expr) – The input as a time-dependent expression

  • U (sympy.Expr) – The input as a Laplace transform (must use symbolic sp.symbols(“s”) if using this option)

  • laplace (bool) – If True, returns Laplace transform Y(s) of the output

dysys.transferfunctionsymbolic.tfs(H, s=None)

Create a TransferFunctionSymbolic object

dysys.transferfunctionsymbolic.s