gftool.polepade.PadeApprox

class gftool.polepade.PadeApprox(zeros: ndarray, poles: ndarray, residues: ndarray, amplitude: ndarray)[source]

Representation of the Padé approximation based on poles.

Basically the approximation is obtained as PoleFct as well as ZeroPole. Note however, that those to approximations will in general not agree. Nevertheless, for a good approximation they should be very similar.

Parameters:

zeros(…, Nz) complex np.ndarray: Zeros of the represented function.
poles, residues(…, Np) complex np.ndarray: Poles and the corresponding residues of the represented function.
amplitude(…) complex np.ndarray or complex: The amplitude of the function. This is also the large abs(z) limit of the function ZeroPole.eval(z) = amplitude * z**(Nz-Np).

__init__(zeros: ndarray, poles: ndarray, residues: ndarray, amplitude: ndarray) → None

Methods

`__init__`(zeros, poles, residues, amplitude)
`eval_polefct`(z)	Evaluate the `PoleFct` representation.
`eval_zeropole`(z)	Evaluate the `ZeroPole` representation.
`moments`(order)	Calculate high-frequency moments of `PoleFct` representation.
`plot`([residue, axis])	Represent the function as scatter plot.

Attributes

`zeros`
`poles`
`residues`
`amplitude`