Evolve / Evolve To...   ()

Summary

Evolves the frontmost simulation forward or backward to a specified time (or date).

Description

When you select this command, an input dialog will be displayed inviting you to specify the time (or date) 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 time (or date) or until you use the Evolve / Stop command to stop it.

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.

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 / Run Backward () which evolves the frontmost simulation backward one time step after another until it is stopped.

• Evolve / Run Forward () which evolves the frontmost simulation forward one time step after another until it is stopped.

• 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 / Time/Date... () which edits the current time (or date) 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.

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