Posts by ictp

On Wednesday 1st of April 2026 starting at 10am, Eduard Grigoriciuc will give a talk at the Institute Seminar.

Title: An Introduction to the Adaptive Antoulas–Anderson Algorithm

Abstract: Rational approximation plays a central role in numerical analysis, with applications ranging from interpolation to model reduction of complex systems. In this introductory talk, we present the Adaptive Antoulas–Anderson (AAA) algorithm, a modern and highly effective method for constructing rational approximations from sampled data. The algorithm combines an adaptive selection of support points with a barycentric representation, enabling stable and accurate approximations without requiring prior knowledge of poles or model structure. We provide the necessary background on rational approximation, outline the main ideas behind the AAA algorithm, and illustrate its behavior through simple examples.