gftool.polepade.asymptotic
- gftool.polepade.asymptotic(z, fct_z, zeros, poles, weight=None)[source]
Calculate large z asymptotic from roots and
poles
.We assume f(z) = a * np.prod(z - zeros) / np.prod(z - poles), therefore The asymptotic for large abs(z) is f(z) ≈ a * z**(zeros.size - poles.size).
- Parameters:
- z, fct_z(N_z) complex np.ndarray
Variable where function is evaluated and function values.
- zeros, poles(n), (m) complex np.ndarray
Position of the zeros and poles of the function.
- weight(N_z) float np.ndarray, optional
Weighting of the data points, for a known error σ this should be weight = 1./σ.
- Returns:
- asym, stdfloat
Large z asymptotic and its standard deviation.