triqs.gf.tools.fit_legendre

triqs.gf.tools.fit_legendre(g_t, order=10)[source]

General fit of a noisy imaginary time Green’s function to a low order Legendre expansion in imaginary time.

Only Hermiticity is imposed on the fit, so discontinuities has to be fixed separately (see the method enforce_discontinuity)

Author: Hugo U.R. Strand

Parameters:

  • g_t (TRIQS imaginary time Green's function (matrix valued)) – Imaginary time Green’s function to fit (possibly noisy binned data)

  • order (int) – Maximal order of the fitted Legendre expansion

Returns:

g_l – Fitted Legendre Green’s function with order order

Return type:

TRIQS Legendre polynomial Green’s function (matrix valued)