AstroGrav Help /Menus /Evolve /Evolve To...Version 3.4
Evolve / Evolve To... ()Operating Systems: All
Window Types: All
Simulation Types: All
Evolves the frontmost simulation forward or backward to a specified date/time.
When you select this command, an input dialog will be displayed inviting you to specify the date/time that you wish the frontmost simulation to evolve to. If you accept the input dialog, AstroGrav will evolve the simulation forward or backward to the specified date/time or until you stop the evolution.
An Animate checkbox allows you to choose whether or not to display the state of the simulation after each time step. If evolution is animated, you can watch the simulation evolve as when you use the Evolve / Run Backward and Evolve / Run Forward commands. While AstroGrav is calculating the next state of the system, the Evolve / Stop command is available for you stop the evolution, and the Evolve / Settings... command is available for you to change the time step. If evolution isn't animated, a progress bar is displayed if evolution is going to take more than a couple of seconds, and a Cancel button is available to stop evolution if desired. Non-animated evolution is usually much faster than animated evolution, so you should only use animated evolution if you want to watch what's happening.
There is also a Beep when finished checkbox that can be useful if you're doing a very long evolution and want an audible alert when it's finished.
The time that it takes AstroGrav to evolve the system through one time step is extremely variable, but depends mainly on the following factors.
- The fewer objects there are in a simulation, the less time it will take to evolve. If there are only a few objects in a simulation, it may evolve through one time step in a tiny fraction of a second, whereas if there are thousands of objects in a simulation, it may take many seconds to evolve through one time step.
- The greater the proportion of objects whose mass is below the mass threshold (specified with the Evolve / Settings... command), the less time it will take to evolve. If a simulation has a significant proportion of objects that have low masses, increasing the mass threshold may significantly reduce the time it takes to evolve, without significantly reducing the accuracy.
- The shorter the time step is, the less time it will take to evolve. Reducing the time step can significantly reduce the time it takes to evolve, but this is not always the case - if the time step is already small, reducing it will have little effect on the evolution time.
- The faster your computer is, the less time it will take to evolve.
- Evolve / Run Backward()that evolves the frontmost simulation backward one time step after another until it is stopped.
- Evolve / Run Forward()that evolves the frontmost simulation forward one time step after another until it is stopped.
- Evolve / Settings...()that sets the evolver settings of the frontmost simulation.
- Evolve / Stop()that stops the evolution of the frontmost simulation.
- Edit / Date/Time...()that edits the current date/time of the frontmost simulation.
- Edit / Undo()that undoes the latest change to the frontmost simulation.
- Edit / Redo()that redoes the most recently undone change to the frontmost simulation.
- Tools / Create Movie...()that creates a movie of the frontmost simulation while it is evolving.
- Tools / Generate Ephemeris...()that generates an ephemeris for an object in the frontmost simulation while it is evolving.
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