Direct Minimization of the least-squares spectral element functional - Part I: Direct solver
                                                article
                                            
                                        
                                                This paper describes an equivalent but improved least-squares formulation for the numerical approximation of the solution of partial differential equations. Instead of using variational analysis to impose the conditions for minimizing the residual, the residuals are minimized directly, thus leading to a method we will denote by Direct Minimization (DM). DM circumvents setting up the normal equations which consists of matrix-matrix multiplications. Matrix-matrix multiplications are expensive, may lead to loss of accuracy and destroy the sparsity pattern present in the original system. The condition number of the DM formulation is the square root of the condition number which would be obtained if variational analysis was employed. An element-by-element procedure will be presented which allows for parallelization of DM. A computational comparison between DM and the conventional least-squares formulation based on variational analysis will be presented. © 2007 Elsevier Inc. All rights reserved.
                                            
                                        Topics
                                            
                                        TNO Identifier
                                            
                                                240625
                                            
                                        ISSN
                                            
                                                00219991
                                            
                                        Source
                                            
                                                Journal of Computational Physics, 227(4), pp. 2411-2429.
                                            
                                        Pages
                                            
                                                2411-2429
                                            
                                        Files
                                            
                                                
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