triqs.gf.backwd_compat.gf_legendre.GfLegendre.from_L_G_R

GfLegendre.from_L_G_R(L, G, R)

Matrix transform of the target space of a matrix valued Greens function.

Sets the current Greens function \(g_{ab}\) to the matrix transform of \(G_{cd}\) using the left and right transform matrices \(L_{ac}\) and \(R_{db}\).

\[g_{ab} = \sum_{cd} L_{ac} G_{cd} R_{db}\]

Parameters:

• L ((a, c) ndarray) – Left side transform matrix.

• G (Gf matrix valued target_shape == (c, d)) – Greens function to transform.

• R ((d, b) ndarray) – Right side transform matrix.

Notes

Only implemented for Greens functions with a single mesh.