Asymmetric proximity matrices

Immediacy matrices in which the off-diagonal elements which are, in the i th row and j th column and the j th row and i th column, are not essentially equal. Examples are given by the number of marriages between men of one nationality and women of another, immigration/emigration statistics and the number of citations of one journal by the other.Multidimensional scaling methods and techniques for such matrices usually rely on their canonical decom- position into the sum of a symmetric matrix and the skew symmetric matrix.