# triqs.gf.backwd_compat.gf_refreq.GfReFreq.from_L_G_R

GfReFreq.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.