“…In addition, sparse grid techniques were successfully applied for the solution of integral equations [25], for quadrature [14], for regression [12] and for time series prediction [5]. Moreover, the sparse grid method was supplemented with adaptive refinement schemes [5,14,22], was used for the construction of anisotropic sparse tensor product spaces [21,20] and was applied in the context of weighted mixed spaces [19,22]. Sparse grid based collocation schemes were for example discussed in [2,26,29,30,33,39].…”