Whats new in version 0.5?

As of yesterday (3/15) I have submitted a new version of momdyn to App Store Connect for the Test Flight beta, and to the Google Play Store for alpha testing. Thats right, finally compiled a version for Android! Besides that, here is a quick summary of whats new in this release:

• New solvers, including with adaptive step sizing
• New rigid body box
• Simulation status is displayed with completion ratio and time step
• Report view is split into pages for each component type

One of the challenges with this project has been finding compatible, pre-existing solvers. Notably, scipy is not easy (perhaps not possible) to compile on iOS or Android, which rules out many of the nice solvers in the scipy.integrate module. For now, I've implemented my own pure Python code that can handle the explicit and adaptive methods here. 

The rigid body box is the first true rigid body component I've added, in other words, it has a moment of inertia tensor, not just point mass. I've been considering various options for how to implement a rigid body interface for a while and ultimately concluded that rather than try to have one method that tries to cover all bases, I will have several individual methods that do one specific thing. So, if this is a sensible, working approach, expect to see cylinders, cones, spheres, etc, in the future with similar interface, 

When you press the play button on the button of the diagram view, you will now see a message on the lower left indicating what step in the process is. underway, and on the right some statistics on the ratio of the simulation completed, and the current step size.

The report view can get to be a pretty long mess of scrolling text with larger models and once equations of motion are generated. To alleviate this, I added the buttons at the top of the screen, tap on the button corresponding to the component you want to see, and it will reduce to that text and that text only.  

momdyn is currently in beta testing for both iOS and Android, if you are interested in joining the beta, send an email to mobilemultibodydynamics@gmail.com.