Nmag micromagnetic simulation tool - software engineering lessons learned
This work provides software engineering lessons for computational science projects, focusing on improving development practices in micromagnetic simulation tools, but it is incremental as it reviews existing decisions rather than introducing new methods.
The paper reviews the design and development of the open-source micromagnetic simulation tool Nmag, highlighting that encapsulating simulation functionality in a Python library provided flexibility and was well-received by users, while noting that overly ambitious code introduced unnecessary complexity and reduced maintainability.
We review design and development decisions and their impact for the open source code Nmag from a software engineering in computational science point of view. We summarise lessons learned and recommendations for future computational science projects. Key lessons include that encapsulating the simulation functionality in a library of a general purpose language, here Python, provides great flexibility in using the software. The choice of Python for the top-level user interface was very well received by users from the science and engineering community. The from-source installation in which required external libraries and dependencies are compiled from a tarball was remarkably robust. In places, the code is a lot more ambitious than necessary, which introduces unnecessary complexity and reduces main- tainability. Tests distributed with the package are useful, although more unit tests and continuous integration would have been desirable. The detailed documentation, together with a tutorial for the usage of the system, was perceived as one of its main strengths by the community.