Elimination on sparse symmetric systems of a special structure

summary:The problem of solving sparse symmetric linear algebraic systems by elimination is discussed. A brief survey of the techniques used is given. Another approach is introduced in the paper. It is more general than the band matrix approach. However, the matrix is not treated element by element as in the most general approach. The procedure for finding the ordering of rows and columns of a matrix suitable for the considered modification of elimination is given. The examples of matrices reordered by the proposed procedure are shown

Elimination on sparse symmetric systems of a special structure

summary:The problem of solving sparse symmetric linear algebraic systems by elimination is discussed. A brief survey of the techniques used is given. Another approach is introduced in the paper. It is more general than the band matrix approach. However, the matrix is not treated element by element as in the most general approach. The procedure for finding the ordering of rows and columns of a matrix suitable for the considered modification of elimination is given. The examples of matrices reordered by the proposed procedure are shown

Reducing the bandwidth in solving linear algebraic systems arising in the finite element method

summary:The matrix of the system of linear algebraic equations, arising in the application of the finite element method to one-dimensional problems, is a bandmatrix. In approximations of high order, the band is very wide but the elements situated far from the diagonal of the matrix are negligibly small as compared with the diagonal elements. The aim of the paper is to show on a model problem that in practice it is possible to work with a matrix of the system the bandwidth of which is reduced. A simple numerical example illustates the discussion