On weak greedy algorithms

Abstract

The main goal of this paper is twofold. First, we extend some results known in the case of weak greedy algorithms with a scalar parameter to the case of weak greedy algorithms with a weakness sequence. Second, we formulate a new setting of the problem of convergence of greedy algorithms. Usually, we are interested in convergence of an algorithm for all elements of the space. We suggest to study convergence of an algorithm for a subset, which is a generalized octahedron associated with a given dictionary.