Tips

Here, a list of useful tips/remarks that, hopefully, will make your life easier.

• The choice of the solver can have huge impact on performance (see How to choose an appropriate solver?).

• If a given matrix is required in several steps, it should be assembled only once (e.g. time-dependent problems).

• Some functions don’t have the expected behavior within a jupyter notebook. This applies mainly to functions imported from dolfin.cpp which task is to print information (e.g. dolfin.cpp.la.list_linear_algebra_backends). This does not mean you should stop using jupyter notebook (they’re very useful!), it simply means you have to go for a script to get this kind of information.

• Code verbosity can change: set_log_level(log_level). In old documentation, you can find set_log_level(DEBUG) and set_log_level(PROGRESS) as the go-to commands. Nevertheless, they do not work in version 2019.1.0, as DEBUG and PROGRESS cannot be imported. To access this variables you have to import LogLevel (from dolfin.cpp.log import LogLevel) and then access the desired variables (e.g. LogLevel.DEBUG). Alternatively , you can use an integer, being log_level=10 and log_level=16, for DEBUG and PROGRESS, respectively. Other options can be found here). I could tell you what each level prints, but why wouldn’t try it yourself? (not in a jupyter notebook!)