[ODE] Consistency
Henri Hakl
henri at cs.sun.ac.za
Tue Mar 18 11:17:01 2003
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Re: [ODE] ConsistencyThat is exactly my problem as well...
The reset seems to work quite well - but something seems fishy. =
Depending on how your simulation works you might have to "reset" the =
joint velocities as well. There might be something else that I haven't =
pin-pointed yet... but rest assured, I'm doing quite a bit of work on =
that issue currently - I'll get post the result once I've figured it =
out. :)
If you catch some catch... please let me know. :)
Henri
----- Original Message -----=20
From: Peggy Skelly=20
To: Henri Hakl=20
Sent: Monday, March 17, 2003 6:39 PM
Subject: Re: [ODE] Consistency
Hi - just a quick question, is ODE deterministically consistent? In =
other words will it (even in complex systems) always produce the same =
results?
Henri,
Does your consistency issue have anything to do with the earlier =
"Reset" question? I also wanted a quick way to reset the initial =
conditions of a simulation, and I liked your solution of just resetting =
the positions, quaternions, linear and angular velocities. So I tried =
that out over the weekend. I found that after resetting, although all =
the positions and velocities were correct (as i set them), the =
simulation proceeded differently. Is there something else that I need to =
reinitialize?
Peggy
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<DIV><FONT face=3DArial size=3D2>That is exactly my problem as =
well...</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>The reset seems to work quite well - =
but something=20
seems fishy. Depending on how your simulation works you might have to =
"reset"=20
the joint velocities as well. There might be something else that I =
haven't=20
pin-pointed yet... but rest assured, I'm doing quite a bit of work on =
that issue=20
currently - I'll get post the result once I've figured it out.=20
:)</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2>If you catch some catch... please let =
me know.=20
:)</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2> Henri</FONT></DIV>
<DIV><FONT face=3DArial size=3D2></FONT> </DIV>
<BLOCKQUOTE dir=3Dltr=20
style=3D"PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; =
BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style=3D"FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV=20
style=3D"BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: =
black"><B>From:</B>=20
<A title=3Dmxs70@po.cwru.edu href=3D"mailto:mxs70@po.cwru.edu">Peggy =
Skelly</A>=20
</DIV>
<DIV style=3D"FONT: 10pt arial"><B>To:</B> <A =
title=3Dhenri@cs.sun.ac.za=20
href=3D"mailto:henri@cs.sun.ac.za">Henri Hakl</A> </DIV>
<DIV style=3D"FONT: 10pt arial"><B>Sent:</B> Monday, March 17, 2003 =
6:39=20
PM</DIV>
<DIV style=3D"FONT: 10pt arial"><B>Subject:</B> Re: [ODE] =
Consistency</DIV>
<DIV><BR></DIV>
<BLOCKQUOTE cite=3D"" type=3D"cite"><FONT face=3DArial size=3D-1>Hi - =
just a quick=20
question, is ODE deterministically consistent? In other words will =
it (even=20
in complex systems) always produce the same =
results?</FONT></BLOCKQUOTE>
<DIV><BR></DIV>
<DIV>Henri,</DIV>
<DIV><BR></DIV>
<DIV>Does your consistency issue have anything to do with the earlier =
"Reset"=20
question? I also wanted a quick way to reset the initial conditions of =
a=20
simulation, and I liked your solution of just resetting the positions, =
quaternions, linear and angular velocities. So I tried that out over =
the=20
weekend. I found that after resetting, although all the positions and=20
velocities were correct (as i set them), the simulation proceeded =
differently.=20
Is there something else that I need to reinitialize?</DIV>
<DIV><BR></DIV>
<DIV>Peggy</DIV></BLOCKQUOTE></BODY></HTML>
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