Extending a scientific application with scripting capabilities

the more changes and additions became inevitable. Your coworkers eventually started asking for a better alternative to the modify-recompile-run routine, so you created an input file-based interface to your application. Suddenly, what used to be a single subroutine now has thousands of lines of code. Some users then decided they wanted a graphical user interface, so you created it using a different language than the one in which you wrote your computational subroutines. To your amazement, your user base quadrupled in three months. You also quickly discovered that making two different languages talk to each other takes more time than successfully replicating cold-fusion experiments. It pleased you to see that more people used your application, but, obviously, more users mean more demands. Now they want to perform optimizations, implement design of experiments, automate frequently performed operations, create 2D and 3D data plots, generate reports automatically, interact with databases, and perform many other tasks that you could not even have dreamed about. To satisfy all these demands, you decide that adding scripting capability to your application was the answer, but what’s the best approach? What’s out there In my own investigations for a similar situation, I discovered that several tools and intermediary languages existed for different platforms that could help different languages talk to each other. From these options, I picked COM (the Component Object Model) to implement scripting capability in Shvib for Windows. Shvib is a shock and vibration analysis program based on Tom Derby’s Fortran subroutines that I have been developing at Barry Controls. Freely and commercially available scripting languages abound out there, but after investigating some of them, I decided to use Python as a scripting language for Shvib. Shvib has a Visual Basic 6 GUI and several Fortran subroutines compiled as Windows DLLs to perform computations (see Figure 1). Because Shvib is a Windows application, COM was the natural choice to glue the Visual Basic GUI, the Fortran DLLs, and Python scripting together.