gftool.pade.calc_iterator¶

gftool.pade.calc_iterator(z_out, z_in, coeff)[source]¶

Calculate Pade continuation of function at points z_out.

The continuation is calculated for different numbers of coefficients taken into account, where the number is in [n_min, n_max]. The algorithm is take from [2].

Parameters

z_outcomplex ndarray: points at with the functions will be evaluated
z_in(N_in,) complex ndarray: complex mesh used to calculate coeff
coeff(…, N_in) complex ndarray: coefficients for Pade, calculated from pade.coefficients

Yields

pade_calc(…, N_in, z_out.shape) complex np.ndarray: Function evaluated at points z_out. numbers of Matsubara frequencies between n_min and n_max. The shape of the elements is the same as coeff.shape with the last dimension corresponding to N_in replaced by the shape of z_out: (…, N_in, *z_out.shape).

References

2: Vidberg, H. J., and J. W. Serene. “Solving the Eliashberg Equations by Means of N-Point Pade Approximants.” Journal of Low Temperature Physics 29, no. 3-4 (November 1, 1977): 179-92. https://doi.org/10.1007/BF00655090.