Curve problem
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From: dirt on 2 May 2010 22:43 Hello, I have generated a curve that is consisting of transient response which is followed by steady state in a form of data points. Is there a way to find out whether the curve has reached steady state or eitherwise... Is it possible to do a loop from the last element of the data? Regards dirt
From: Walter Roberson on 2 May 2010 22:51 dirt wrote: > I have generated a curve that is consisting of transient response which > is followed by steady state in a form of data points. Is there a way to > find out whether the curve has reached steady state or eitherwise... Is > it possible to do a loop from the last element of the data? I'm not sure if this is what you are after, but: for K = length(V):-1:1 .... V(K) end would loop backwards on V. I can think of more than one variety of "steady state". In some of them, you can check find the end of the unsteadiness via a test similar to find( abs(diff(V)) > NoiseLevel, 1, 'last' ) In other varieties of "steady state", find( abs(diff(log(V))) > NoiseLevel, 1, 'last' ) would be appropriate
From: dirt on 2 May 2010 23:35 Walter Roberson <roberson(a)hushmail.com> wrote in message <tSqDn.118852$kj3.75722(a)newsfe08.iad>... > dirt wrote: > > > I have generated a curve that is consisting of transient response which > > is followed by steady state in a form of data points. Is there a way to > > find out whether the curve has reached steady state or eitherwise... Is > > it possible to do a loop from the last element of the data? > > I'm not sure if this is what you are after, but: > > for K = length(V):-1:1 > .... V(K) > end > > would loop backwards on V. > > > > I can think of more than one variety of "steady state". In some of them, > you can check find the end of the unsteadiness via a test similar to > > find( abs(diff(V)) > NoiseLevel, 1, 'last' ) > > In other varieties of "steady state", > > find( abs(diff(log(V))) > NoiseLevel, 1, 'last' ) > > would be appropriate May i ask what is 'NoiseLevel',1,'last' refers to? regards dirt
From: John D'Errico on 2 May 2010 23:44 "dirt " <posto86(a)hotmail.com> wrote in message <hrld7o$qdu$1(a)fred.mathworks.com>... > Hello, > > I have generated a curve that is consisting of transient response which is followed by steady state in a form of data points. Is there a way to find out whether the curve has reached steady state or eitherwise... Is it possible to do a loop from the last element of the data? > No. You can never KNOW what will happen, simply from a sampling of values. John
From: dirt on 3 May 2010 01:34
"John D'Errico" <woodchips(a)rochester.rr.com> wrote in message <hrlgq3$dls$1(a)fred.mathworks.com>... > "dirt " <posto86(a)hotmail.com> wrote in message <hrld7o$qdu$1(a)fred.mathworks.com>... > > Hello, > > > > I have generated a curve that is consisting of transient response which is followed by steady state in a form of data points. Is there a way to find out whether the curve has reached steady state or eitherwise... Is it possible to do a loop from the last element of the data? > > > > No. You can never KNOW what will happen, simply from > a sampling of values. > > John Why is that so? Can u give a brief explaination? Regards dirt |