%T Information complexity of functional optimization problems and their approximation schemes %P 303-317 %J Mathematics in Engineering, Science and Aerospace (MESA) %N 3 %L eprints1703 %V 1 %A Giorgio Gnecco %A Marcello Sanguineti %D 2010 %X Functional optimization is investigated using tools from information-based complexity. In such optimization problems, a functional has to be minimized with respect to admissible solutions belonging to an infinite-dimensional space of functions. This context models tasks arising in optimal control, systems identification, machine learning, time-series analysis, etc. The solution via variable-basis approximation schemes, which provide a sequence of nonlinear programming problems approximating the original functional one, is considered. Also for such problems, the information complexity is estimated.