pyMDO

Abstract

We present pyMDO, an object-oriented framework that facilitates the usage and development of algorithms for multidisciplinary optimization (MDO). The resulting implementation of the MDO methods is efficient and portable. The main advantage of the proposed framework is that it is flexible, with a strong emphasis on object-oriented classes and operator overloading, and it is therefore useful for the rapid development and evaluation of new MDO methods. The top layer interface is programmed in Python and it allows for the layers below the interface to be programmed in C, C++, Fortran, and other languages. We describe an implementation of pyMDO and demonstrate that we can take advantage of object-oriented programming to obtain intuitive, easy-to-read, and easy-to-develop codes that are at the same time efficient. This allows developers to focus on the new algorithms they are developing and testing, rather than on implementation details. Examples demonstrate the user interface and the corresponding results show that the various MDO methods yield the correct solutions.

Extensions to the design structure matrix for the description of multidisciplinary design, analysis, and optimization processes

“…UML was designed to model and visualize software systems, especially objectoriented software, under a unified standard. (An example of UML class diagrams is given by Martins et al (2009).) Because of the close connections between object-oriented software and MDO (Alexandrov and Lewis 2004a, b), we may expect that the same visualization tools can be used in both cases.…”

“…Finally, a diagram that is common in systems engineering is the N 2 diagram (Lano 1977) or design structure matrix (DSM) (Steward 1981). An example DSM for an aircraft design problem is shown in Fig.…”

“…While we have not explored this idea in more detail, we believe that there are more cases in which XDSMs could be used as visualization tools. An important application of the XDSM is in MDO software frameworks such as iSight, ModelCenter, pyMDO (Martins et al 2009), andOpenMDAO (Gray et al 2010). These are tools developed to assist engineers in integrating multiple analysis codes to run various analysis and optimization processes.…”

“…Another language, called χ, was created by Etman et al (2005) to specify the coordination strategy for parallel solution processes. While linguistic approaches like these are useful for automatically implementing MDO architectures in a computational environment (Martins et al 2009), they do not provide a formal visual representation of how the architecture handles the original problem.…”

OpenMDAO: an open-source framework for multidisciplinary design, analysis, and optimization

“…To facilitate the exploration of the various MDO architectures, Tedford and Martins (2006) developed pyMDO. This was the first object-oriented framework that focused on automating the implementation of different MDO architectures (Martins et al 2009). In pyMDO, the user defined the general MDO problem once, and the framework would reformulate the problem in any architecture with no further user effort.…”