This function gives the initial value for 1D algorithm, which is searched from the eigenvectors of matrices M and M+U corresponding to their objective function value.
get_ini1D(M, U)M matrix in the envelope objective function. A \(p\)-by-\(p\) positive semi-definite matrix.
U matrix in the envelope objective function. A \(p\)-by-\(p\) positive semi-definite matrix.
Return initial value for the 1D algorithm.