Approximation of multivariate periodic functions based on sampling along multiple rank-1 lattices
For researchers in high-dimensional function approximation, this provides a practical sampling scheme with improved convergence rates, though it is an incremental improvement over existing rank-1 lattice methods.
The paper proposes reconstructing high-dimensional periodic functions using multiple rank-1 lattices, achieving sampling error estimates in Sobolev spaces with an exponent nearly twice as good as single rank-1 lattice sampling (within 1/2+ε of optimal). Numerical tests confirm the theoretical results.
In this work, we consider the approximate reconstruction of high-dimensional periodic functions based on sampling values. As sampling schemes, we utilize so-called reconstructing multiple rank-1 lattices, which combine several preferable properties such as easy constructability, the existence of high-dimensional fast Fourier transform algorithms, high reliability, and low oversampling factors. Especially, we show error estimates for functions from Sobolev Hilbert spaces of generalized mixed smoothness. For instance, when measuring the sampling error in the $L_2$-norm, we show sampling error estimates where the exponent of the main part reaches those of the optimal sampling rate except for an offset of $1/2+\varepsilon$, i.e., the exponent is almost a factor of two better up to the mentioned offset compared to single rank-1 lattice sampling. Various numerical tests in medium and high dimensions demonstrate the high performance and confirm the obtained theoretical results of multiple rank-1 lattice sampling.