International Journal of Mathematics and Mathematical Sciences
Volume 2006 (2006), Issue 17, Article ID 87392, 5 pages
doi:10.1155/IJMMS/2006/87392

A note on comprehensive backward biorthogonalization

Abstract

We present a backward biorthogonalization technique for giving an orthogonal projection of a biorthogonal expansion onto a smaller subspace, reducing the dimension of the initial space by dropping d basis functions. We also determine which basis functions should be dropped to minimize the L2 distance between a given function and its projection. This generalizes some results in [3].