Thomas Viklands; Ume√•; has developed an algorithm and furthered the analysis for one problem of this kind; the Penrose-Procrustes regression problem. Viklands has shown that this problem can have 2n local minima. Here n is the number of orthogonal vectors for which the optimization problem is defined. Vikland¬īs algorithm tries to find all the minima of the P-P problem.
In this talk we will summarize the state of the art of the research in this area with special emphasis on the Penrose-Procrustes regression problem.