perturbation.identify_transfer_matrix

perturbation.identify_transfer_matrix(
    prob,
    x_bar,
    measured,
    *,
    node,
    a,
    b,
    excite=None,
    isentropic=False,
    forcing=None,
    freeze=(),
    continue_=True,
    eps=None,
    eps_fb=1e-06,
    u_floor=1e-08,
    **fit_kwargs,
)

Recover the 2-port transfer matrix of any interior element from a network measurement.

Works for a marked :func:~nefes.elements.catalog.transfer_matrix_element and for any ordinary interior 2-port element whose linear transfer matrix you want to extract – e.g. an :func:~nefes.elements.catalog.equilibrium_flame. The element keeps its own mean-flow kernel (heat addition, dilatation, area change); only its perturbation acoustic rows are treated as the unknown block, so the recovered matrix is the element’s full linear 2-port (a flame’s active response folds into it).

Parameters

Name Type Description Default
prob CompiledProblem or Solution The network. node is any interior 2-port element; any dynamic-source feedback it carries is folded into the recovered matrix (the identification runs it silent). Pass a solved :class:nefes.Solution to have its problem and mean state supplied for you (then omit x_bar). required
x_bar ndarray Converged mean-flow state. Omit when prob is a Solution. required
measured TransferMatrix Measured transfer matrix w_b = M_meas w_a between edges a and b; its grid sets the identification frequencies and its dimension N the matrix recovered. required
node int The element’s node id. required
a int Edge ids the measured matrix spans (a upstream of the element, b downstream). required
b int Edge ids the measured matrix spans (a upstream of the element, b downstream). required
excite sequence of str Driven wave families (default: ("acoustic", "entropy") for N=3, else ("acoustic",)). None
isentropic bool Pin the entropy wave to zero everywhere (rho' = p'/c^2) – the acoustics-only identification (N=2). Use this when the measured matrix is a purely acoustic 2-port and entropy generation should not contaminate the recovery; the measured matrix must have been taken (or synthesized) under the same assumption. The flag pins only the entropy characteristic – a transported reacting scalar is left untouched – but with N=2 and an acoustic-only excitation the recovered 2-port carries neither entropy nor scalar channels. Default False (full acoustic+entropy). False
forcing optional Passed to the measurement driver (which terminals to drive / keep physical). None
freeze optional Passed to the measurement driver (which terminals to drive / keep physical). None
continue_ bool Also fit a rational continuation of the recovered matrix (default True). True
**fit_kwargs Forwarded to :meth:TransferMatrix.continue_ (e.g. rtol, delay). {}

Returns

Name Type Description
TransferMatrixIdentification
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