Evolves the frontmost simulation backward one time step.
Description
When you select this command, the frontmost simulation will evolve backward one time step.
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. In many simulations though, the calculations will be completed in a fraction of a second, and you will not notice this.
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 less 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 fraction of a second, wheras if there are thousands of objects in a simulation, it may take several minutes to evolve through one time step.
The greater the proportion of zero mass objects there are, the less time it will take to evolve. If a simulation has a significant proportion of objects that have small but non-zero masses, changing their masses to zero 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.
See Also:
Evolve / Settings...
()
which sets the time step of the frontmost simulation to a specified value.
Evolve / Stop
()
which stops the evolution of the frontmost simulation.
Edit / Undo
()
which undoes the latest change to the frontmost simulation.
Edit / Redo
()
which redoes the most recently undone change to the frontmost simulation.
)
AstroGrav Help /
Menus /
Evolve /
Step Backward
)
which sets the time step of the frontmost simulation to a specified value.
)
which stops the evolution of the frontmost simulation.
)
which undoes the latest change to the frontmost simulation.
)
which redoes the most recently undone change to the frontmost simulation.