Quantities resulting from application of the WFA. From top to bottom, the four rows show the quantities for the Fe10747, Fe5303, Si14301, and Si39343 lines. Left column: Line-of-sight magnetic fields, inferred through the application of the WFA to the synthetic profiles obtained from P-CORONA (see text). Central column: Pearson coefficient for the correlation between the V(λ) and ∂I(λ)/∂λ synthetic profiles, at each point on the PoS. Right column: Square relative error between the V(λ) profiles resulting from the synthesis and from the application of the WFA.