This book introduces general theory by presenting the most important facts on multivariate interpolation, quadrature, orthogonal projections and their summation, all treated under a constructive view, and embedded in the theory of positive linear operators. On this background, the book builds the first comprehensive introduction to the theory of generalized hyperinterpolation. Several parts of the book are based on rotation principles, which are presented in the beginning of the book.

Inhalt

1 Basic Principles and Facts.- 2 Gegenbauer Polynomials.- 3 Multivariate Polynomials.- 4 Polynomials on Sphere and Ball.- 5 Approximation Methods.- 6 Approximation on the Sphere.- 7 Approximation on the Ball.- 8 Tomography.- A Legendre Basis.- B Zeros of the Kernel Function.- C Newman-Shapiro Operators.- D Reconstruction.- E Solutions.