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 30: The step-26 tutorial program -- the heat equation. Part 2: Adaptive meshes for time dependent problems

In this second lecture on the implementation of time dependent problems (using the step-26 tutorial program), I look at practical questions surrounding how to choose meshes that are adapted between time steps to follow the changing solution. In particular, this includes questions of how to deal with forming the right hand side of the PDE that needs to be solved in each time step and the involves the solution obtained in the previous time step on a (possibly) different mesh. I also discuss questions on how to actually do the mesh refinement in the context of time dependent problems.

Slides: click here