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[oscill8-help] Re: Issues with Oscill8
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From: Emery C. <ec...@vt...> - 2005-09-12 15:37:59
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Vijay,<br>
<br>
Now that limit cycle continuation works, that would be your preferred
method to get period/min/max done (although it may take longer). You
first must have a good 1 parameter bifurcation diagram; then continue
from a HB using limit cycle continuation. The output is the same as
that from sample period/min/max, but is more intelligent (see attached
png). BEWARE that limit cycle continuation can take a VERY long time if
you leave the settings ds, dsmin and dsmax as they are, but you will
have nice results. If you set ds, dsmin too large, you will get
spurious results (they should be obviously bad...).<br>
<br>
BUT, if you want a quick sampling, this can be very quick IF YOU SET
THE PARAMETERS CORRECTLY. This requires that you study the wave forms
and changes in period for some small perturbations BEFORE RUNNING THE
SAMPLING! If you want to use the sample period/min/max, you need to
ensure that dp is small enough so that you get several samples within
the region of oscillation (i.e., look at the 1p bd first), but make
sure that x_match_tol and period_match_tol is large enough (I changed
period_max = 10000, x_match_tol = 60, period_match_tol = 10 to get the
second attached graph). Sometimes you will get inaccuracies or
anomalies, but you can cut these out of the data set...<br>
<br>
It all takes work, but you just must be patient and analyze the system
locally to get the basic behavior, and then set your parameters.<br>
<br>
FYI, limit cycle continuation works MUCH BETTER, but is slower; once
you have a basic picture with the "sample period/min/max" run a
lengthy, accurate limit cycle continuation to get nicer graphs.<br>
<br>
[BTW, I added you and Herbert to the oscill8-help list; this is where
all the hints and help will go to from now on]<br>
<br>
Emery<br>
<br>
<br>
<br>
Vijay Chickarmane wrote:
<blockquote
cite="mid...@de..."
type="cite">
<blockquote style="margin-right: 0px;" dir="ltr">
<span class="104151705-10092005"><font face="Tahoma" size="2">Hi
Emory,</font></span>
<blockquote style="margin-right: 0px;" dir="ltr">
<div><span class="104151705-10092005"><font face="Tahoma" size="2">I am
having trouble with the min-max of oscillations for a couple of models,
so I would be</font></span></div>
<div><span class="104151705-10092005"><font face="Tahoma" size="2">grateful
for your help. I tried to get the max-min for the foll</font></span></div>
<div><span class="104151705-10092005"><font face="Tahoma" size="2">two
models, but was unable to. Could you try and generate the plots, </font></span><span
class="104151705-10092005"><font face="Tahoma" size="2">and send them
as well</font></span></div>
<div><span class="104151705-10092005"><font face="Tahoma" size="2">as
the parameter settings you used to generate them.</font></span></div>
<div><span class="104151705-10092005"></span> </div>
<div><span class="104151705-10092005"></span><span
class="104151705-10092005"><font face="Tahoma" size="2">model 1:
mapkfinal.xml ------ bifurcation parameter J5_k (currently set at
0.0001)</font></span></div>
<div><span class="104151705-10092005"></span> </div>
<div><span class="104151705-10092005"><font face="Tahoma" size="2">model
2: mapknew.xml ------- bifurcation parameter kI (currently set at
100)</font></span></div>
<div><span class="104151705-10092005"></span> </div>
<div><span class="104151705-10092005"><font face="Tahoma" size="2">Thanks
in advance,</font></span></div>
<div><span class="104151705-10092005"><font face="Tahoma" size="2">best,</font></span></div>
<div><span class="104151705-10092005"><font face="Tahoma" size="2">vijay</font></span></div>
</blockquote>
</blockquote>
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