Figure 3
Comparison of the OMP and the locally optimal algorithm: let x , f1, f2 lie on the same plane, but f3 stem out of this plane. At the first step both algorithms choose f1 (min angle with x) and calculate the error vector e2. At the second step the OMP algorithm chooses f3 because ∡(e2, f3) <∡(e2, f2). The locally optimal algorithm makes the optimal choice f2 since e2 and f2orth are collinear.