Solving the Biharmonic Equation in a Square: A Direct Versus a Semidirect Method Two methods for solving the biharmonic equation are compared. One method is direct, using eigenvalue-eigenvector decomposition. The other method is iterative, solving a Poisson equation directly at each iteration. CACM November, 1973 Ehrlich, L. W. biharmonic, direct method, block iterative, eigenvector-eigenvalue decomposition 5.14 5.17 CA731118 JB January 19, 1978 3:28 PM 2408 5 2408 2408 5 2408 2408 5 2408