Build_JTree             Build a hierarchical/wavelet tree of 2-by-2
                        Jacobi rotations
Calc_Energy             A little function calculate the energy of each
                        level
Get_C                   a function to Get the (1) Covariance matrix (2)
                        correlation matrix
JTree_Basis             Calculate the basis for the Jacobi tree
                        algorithm (one or more iterations)
JTree_Scores            Calculates scores for the "best K-basis" at
                        each level of the tree
Run_JTree               The function computes the basis representation
                        of the matrix at maxlev
Score_JTree             The function computes the scores for the best K
                        basis, for each level of the tree
flip                    a little function which is equal to flipud in
                        matlab,make the matrix"upside-down"
