  IFISS is an established MATLAB finite element software package for studying
strategies for solving partial differential equations (PDEs). IFISS3D is a new
add-on toolbox that extends IFISS capabilities for elliptic PDEs from two to
three space dimensions. The open-source MATLAB framework provides a
computational laboratory for experimentation and exploration of finite element
approximation and error estimation, as well as iterative solvers. The package
is designed to be useful as a teaching tool for instructors and students who
want to learn about state-of-the-art finite element methodology. It will also
be useful for researchers as a source of reproducible test matrices of
arbitrarily large dimension.
