perturbation.identify_transfer_function

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

Recover the transfer function(s) of a marked flame / mass-source feedback.

The element at node carries a :class:~nefes.elements.dynamic_source.DynamicSource built with :func:~nefes.perturbation.identify.unknown_dynamic_source; each of its terms names a reference edge and quantity, and one transfer function per term is recovered from the measured transfer matrix between edges a and b.

One measured matrix separates the terms only when its excitations make the reference fluctuations linearly independent; otherwise the per-frequency system is rank-deficient (reported by :attr:TransferFunctionIdentification.conditioning) and multiple loading conditions are needed.

Parameters

Name Type Description Default
prob As for :func:identify_transfer_matrix; excite defaults to the full acoustic+entropy set (more channels -> better conditioning). required
x_bar As for :func:identify_transfer_matrix; excite defaults to the full acoustic+entropy set (more channels -> better conditioning). required
measured As for :func:identify_transfer_matrix; excite defaults to the full acoustic+entropy set (more channels -> better conditioning). required
node As for :func:identify_transfer_matrix; excite defaults to the full acoustic+entropy set (more channels -> better conditioning). required
a As for :func:identify_transfer_matrix; excite defaults to the full acoustic+entropy set (more channels -> better conditioning). required
b As for :func:identify_transfer_matrix; excite defaults to the full acoustic+entropy set (more channels -> better conditioning). required
excite As for :func:identify_transfer_matrix; excite defaults to the full acoustic+entropy set (more channels -> better conditioning). required
forcing As for :func:identify_transfer_matrix; excite defaults to the full acoustic+entropy set (more channels -> better conditioning). required
freeze As for :func:identify_transfer_matrix; excite defaults to the full acoustic+entropy set (more channels -> better conditioning). required
continue_ As for :func:identify_transfer_matrix; excite defaults to the full acoustic+entropy set (more channels -> better conditioning). required
isentropic bool Pin the entropy wave to zero everywhere (acoustics-only); excite is then reduced to its acoustic entry and the measured matrix must be the matching acoustic 2-port. Only the entropy characteristic is pinned – a transported reacting scalar is left untouched. Default False. False
**fit_kwargs Forwarded to :class:~nefes.perturbation.continuation.RationalFit. {}

Returns

Name Type Description
TransferFunctionIdentification
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