PROBID - Preference Ranking on the Basis of Ideal-Average Distance
1. Vector-normalize every criterion column. Criterion direction is not applied here; benefit/cost ordering is applied when the ideal solutions are constructed in F3.
2. Weighted normalized matrix v_ij = w_j · r_ij.
3. Construct m ideal solutions A(k): each column of wnmatrix sorted in descending order. Average ideal solution Ā_j = (1/m) Σ_k A(k)_j.
4. Euclidean distances: S_i(k) = distance from alt i to k-th ideal A(k); S_i(avg) = distance from alt i to average ideal Ā.
5. Harmonic-weighted positive and negative ideal distances. S_pos uses k=1,…,⌈m/2⌉; S_neg uses k=⌊m/2⌋+1,…,m, so the middle ideal is shared only when m is odd. Then R_i=S_pos_i/S_neg_i and p_i=1/(1+R_i²)+S_i(avg), ranked descending.