.. _`Chap:BasAdapt`:

Basis Adaptation Models
=======================

The idea behind the basis adaptation is similar to the one employed in
the active subspaces that is to find the directions in the input space
where the variations of the QoI are negligible. One of the main
differences between the basis adaptation and the active subspaces
strategy is that the basis adaptation rely on the construction of a
Polynomial Chaos Expansion (PCE) that is subsequently rotated to
decrease the dimensionality of the problem.
