Accurate accuracy mode is less accurate

[komatii]

It seems like the accurate accuracy mode is less accurate. As I increase the time step, orbiting bodies fly off into space much quicker with the accurate mode. Even with systems modeled off real world ones, such as our solar system, and earth and moon; normal mode seems to hold the orbits as stable for twice as long as accurate mode while steadily increasing the time step.

komatii

[vh]

this is because accuracy mode is slower and thus, it takes more time for your computer to calculate. So, when you speed both simulations up, the one with accuracy mode gets turned up to a higher timestep and is as a result, less stable.

Also, i think the accuracy only works on dust? i saw a notice in the sim about that or something.

but auto timestep is a great tool, just press "A"

[FiahOwl]

this is because accuracy mode is slower and thus, it takes more time for your computer to calculate. So, when you speed both simulations up, the one with accuracy mode gets turned up to a higher timestep and is as a result, less stable.

Also, i think the accuracy only works on dust? i saw a notice in the sim about that or something.

but auto timestep is a great tool, just press "A"

Accuracy works on orbits.

[vh]

um, if you mouse-over the accuracy thing, it says something about applying only to dust, unless that has been removed/fixd

[atomic7732]

but auto timestep is a great tool, just press "A"

I believe there's a downfall there. Create two planets of any mass, one with an eccentric orbit (around 0.5) and one with any type of orbit outside of it (as long as it doesn't cross inside the inner planet's orbit at any time). Let the simulation run, and with auto-timestep the inner object's orbit gets circular.

[vh]

ugh, that reminds me of auto-orbit, i hate how the inclinations and eccentricities get messed up by that!

and also auto timestep messes up sometimes
if you had an orbiting body with high eccentricity, when it gets close to the other body, autotimestep can't slow it down fast enough and it slingshots off/does something wierd

[dhm794]

This is made clear in the FAQ.

[Dan Dixon]

It seems like the accurate accuracy mode is less accurate...

Good observation. Turns out the accurate mode (RK4) is less accurate at extreme speeds (when everything flies apart) than Euler mode, but more accurate at slower speeds.