The convergence of least squares approximations for dual orthogonal series
- 1 March 1974
- journal article
- research article
- Published by Cambridge University Press (CUP) in Glasgow Mathematical Journal
- Vol. 15 (1) , 82-84
- https://doi.org/10.1017/s0017089500002184
Abstract
The convergence of least squares approximations for dual orthogonal series in Hilbert space is established, thus providing a theorem applicable to practically all dual orthogonal series (such as dual trigonometric series, dual Bessel series, etc.) that have appeared in the literature. Our results establish for such dual series the existence of a sequence of functions satisfying in the L2norm the dual series relation, with an error tending to zero and, in particular, rigorously justify the calculations in [2] which showed least squares to be a practical approximation procedure for dual trigonometric equations. In fact, the desire to provide a rigorous convergence theorem for [2] motivated this study.Keywords
This publication has 1 reference indexed in Scilit:
- Least squares approximations for dual trigonometric seriesGlasgow Mathematical Journal, 1973