2012/01/01 by William McLean · 6 citations
Mathematics · Physics and Astronomy · #Differential Equations and Numerical Methods #Fractional Differential Equations Solutions #Model Reduction and Neural Networks
paper · doi:10.1137/120870505
openalex publication_date 2012/01/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/30
We solve a fractional diffusion equation using a piecewise-constant, discontinuous Galerkin method in time combined with a continuous, piecewise-linear finite element method in space. If there are N time levels and M spatial degrees of freedom, then a direct implementation of this method requires O(N2M) operations and O(NM) active memory locations, owing to the presence of a memory term: at each time step, the discrete evolution equation involves a sum over all previous time levels. We show how the computational cost can be reduced to O(MNlog N) operations and O(Mlog N) active memory locations.