gftool.basis.pole.PoleGf.from_moments
- classmethod PoleGf.from_moments(moments, width=1.0)
Generate instance matching high-frequency
moments
.- Parameters:
- moments(…, N) float array_like
Moments of the high-frequency expansion, where g(z) = moments / z**np.arange(1, N+1) for large z.
- widthfloat or (…) float array_like or None, optional
Spread of the poles; they are in the interval [-width, width]. width=1 are the normal Chebyshev nodes in the interval [-1, 1]. If width=None and the second moment moments[…, 1] is given, the largest pole will match the second moment, unless it is small (abs(moments[…, 1]) < 0.1), then we choose width=1.
- Returns:
- PoleFct
Pole function with high-frequency
moments
.
See also
gf_from_moments
Contains the details how
PoleFct
is constructed.