RT info:eu-repo/semantics/article T1 A comparison of one-step and two-step W-methods and peer methods with approximate matrix factorization A1 Hernández Abreu, Domingo A1 Klinge, M. A1 Weiner, R. A2 Análisis Matemático A2 Grupo de investigación ULL: "Métodos numéricos en ecuaciones diferenciales" https://www.ull.es/grupoinvestigacion/met-numericos-ec-diferenciales/ K1 Approximate matrix factorization K1 stability K1 W-methods K1 two-step W-methods K1 peer methods K1 convection-diffusion-reaction PDEs AB One- and Two-step W-methods and peer methods are considered combined with an Approximate Matrix Factorization (AMF) for the numerical solution of large systems of stiff Ordinary Differential Equations (ODEs) coming from the spatial discretization of parabolic Partial Differential Equations (PDEs)of convection-diffusion-reaction type. Although one-step AMF W-methods do not require starting values and have larger stability regions, they may suffer from order reduction for such PDE problems when timedependent Dirichlet boundary conditions are imposed. Here by numerical tests it is illustrated that two-step AMF W-methods and AMF peer methods avoid this order reduction (in stiff sense, i.e. for a fixed spatial grid) due to their high stage order. On the other hand, while AMF W-methods are linearly implicit, AMFpeer methods require the solution of nonlinear equations in order to compute an advancing solution. In this case, the predictor considered for the internal stages influences both stability and accuracy. However, with only one Newton iteration, for a given number of stages, the three classes of methods have a similar computational cost. YR 2019 FD 2019 LK http://riull.ull.es/xmlui/handle/915/39059 UL http://riull.ull.es/xmlui/handle/915/39059 LA en DS Repositorio institucional de la Universidad de La Laguna RD 21-nov-2024