Version 2.1 - 30th June 2013
Version 2.1 of AstroGrav is an upgrade containing many significant improvements and bug fixes. This information is intended for existing users who are already familiar with AstroGrav and want to quickly find out about the main changes. This is a free upgrade for customers who have already purchased a license, so that all you need to do is download Version 2.1 and use it in place of your old version. If you have any problems with this new version, please don't hesitate to contact us so that we can help you out.
Version 2.1 of AstroGrav has the following new and improved features.
Simulation Evolution
Version 2.1 of AstroGrav includes the following improvements and bug fixes to simulation evolution.
- Evolution of very large systems has been greatly speeded up, particularly ones in which most objects have masses below the evolution mass threshold.
- A bug has been fixed that made evolution inaccurate when general relativity was being used. In most cases, the inaccuracy was very small, but could be large for near-parabolic orbits.
- Bouncing collisions have been greatly improved, so that it is now possible to simulate rubble piles and their collisions. A bug has also been fixed that caused simulations with bouncing collisions to produce different results on different runs with multi-processor/core computers.
- A bug has been fixed that occasionally caused the Evolve / Evolve To... command to fail to complete, particularly when using a long time step.
- A bug has been fixed that could cause a two-dimensional system (such as one in which the z-coordinate of every object is zero) to evolve into a three-dimensional system.
- A bug has been fixed that could cause some updates of view windows to be omitted when running a simulation, resulting in jerky animation.
- A bug has been fixed that could cause processing power to continue to be used after evolution had been stopped.
Solar System Orbital Elements
In earlier versions of AstroGrav, the orbital elements of an object were always calculated with respect to the barycenter of the parent object and any 'inferior' objects - for example, the Earth's orbital elements were calculated with respect to the barycenter of the Sun, Mercury, and Venus. While this works very well in many cases, it is inconsistent with the conventions that are usually used for the solar system. As a result, AstroGrav's solar system orbital elements were often significantly different to published figures and other software, and in cases of near-parabolic orbits (such as comets in the inner solar system) the differences could be very large. In version 2.1 of AstroGrav, this problem has been solved by calculating the orbital elements of a solar system object with respect to the Sun alone.
The change to the way that orbital elements are calculated applies only to solar system simulations. Other simulations continue to have their orbital elements calculated as before.
The accuracy of the orbital elements of near-parabolic orbits has also been improved, both for solar system simulations and non-solar system simulations.
Importing Objects
Version 2.1 of AstroGrav includes the following improvement and bug fixes to the importing of objects into solar system simulations using the Edit / Import Objects... command.
- More Accurate and Less Accurate labels have been added to the JPL and MPC options on the choice dialog.
- A bug has been fixed that often caused AstroGrav to crash when downloading large sets of JPL data.
- A bug has been fixed that often caused the thermometer on the progress monitor to bobble back and forth as the date display changed during slow import evolution.
- A bug has been fixed that could cause the evolution preceding a slow comet import to fail to complete.
Other Improvements
Version 2.1 of AstroGrav also has many other minor improvements and bug fixes, including the following.
- Major performance improvements have been made for handling simulations that contain a large number of objects.
- Closing windows and exiting/quitting AstroGrav have both been greatly speeded up.
- A bug has been fixed that could cause negative angles to get rounded incorrectly.
- A bug has been fixed that often caused the right ascension '0h 00m' to be overlaid with '24h 00m' on the display of the celestial equator.
- A bug has been fixed that caused the fixed object on a view window to fail to revert to the center of mass following its deletion.
- A bug has been fixed that caused the fixed object on a view window to fail to remain fixed after deleting the object being viewed from.
- The name of the View / Background / Less Star Names command has been changed to View / Background / Fewer Star Names.
- Support has been added for Retina displays.