On matrix solutions of discretized Dirichlet and Neumann problems
Victor Lovass-Nagy, David L. Powers · International Journal of Systems Science · 1975
An algorithm is described for solving block-tridiagonal systems of equations. If the block-dimension is q, then q systems, each the size of one block, are to be solved. For certain values of q, the Fast Fourier Transform may be employed to speed the work. Other simplifications and extensions to singular problems are discussed.