TY - JOUR T1 - A Fast Algorithm for the Caputo Fractional Derivative JO - East Asian Journal on Applied Mathematics VL - 4 SP - 656 EP - 677 PY - 2018 DA - 2018/10 SN - 8 DO - http://doi.org/10.4208/eajam.080418.200618 UR - https://global-sci.org/intro/article_detail/eajam/12813.html KW - Caputo derivative, fast algorithm, polynomial approximation, error, graded mesh. AB -

A fast algorithm with almost optimal memory for the computation of Caputo’s fractional derivative is developed. It is based on a nonuniform splitting of the time interval [0, $t_n$] and a polynomial approximation of the kernel function $(1−τ)^{−α}$. Both the storage requirements and the computational cost are reduced from $\mathscr{O}(n)$ to $(K +1)\mathscr{O}(log~n)$ with $K$ being the degree of the approximated polynomial. The algorithm is applied to linear and nonlinear fractional diffusion equations. Numerical results show that this scheme and the corresponding direct methods have the same order of convergence but the method proposed performs better in terms of computational time.