Starting in the spring 2013, I videotaped the lectures for my MATH 676: Finite element methods in scientific computing course at the KAMU TV studio at Texas A&M. These are lectures on many aspects of scientific computing, software, and the practical aspects of the finite element method, as well as their implementation in the deal.II software library. Support for creating these videos was also provided by the National Science Foundation and the Computational Infrastructure in Geodynamics.

Note 1: In some of the videos, I demonstrate code or user interfaces. If you can't read the text, change the video quality by clicking on the "gear" symbol at the bottom right of the YouTube player.

Note 2: deal.II is an actively developed library, and in the course of this development we occasionally deprecate and remove functionality. In some cases, this implies that we also change tutorial programs, but the nature of videos is that this is not reflected in something that may have been recorded years ago. If in doubt, consult the current version of the tutorial.

Lecture 37: What preconditioner to use — Part 4: Simple preconditioners for complex problems

Given the preconditioners discussed in the previous two lectures for "simple" problems, one may ask how they can be generalized to more complex problems such as the Stokes equation or coupled multiphysics problems. This lecture outlines a few of the ideas people have used in this regard, in particular the generalization of point solvers and Vanka-type preconditioners. Most of these methods do not actually work very well in practice, but it is important to understand their limitations to understand why we consider the alternatives discussed in the next lecture.

Slides: click here