Hi,
In connection with this topic, I have a question about the rates analysis
(I might ask this before but haven't yet solved the problem). Could anyone
answer this?
When I click the Group Peaks button in the Rate Measurements popup after I
set up reference peak list, experiment series etc., Analysis gives the
table of 'Peak Groups' but the TC Error colomn is filled by 0 at this
stage. When I use either Recalculate Rates button or Show function fit
button, TC Error is given just one by one, but at the same time, Rate, TC
and possibly Fit Error values change from the original values in the
table. Is this right? Which values can I trust? Can I get correct values
and TC errors only after recalculating rates on eby one, or is there any
way to get the values in one go?
Kaeko
On Mon, 27 Feb 2006, Wayne Boucher wrote:
> Hello,
>
> The fitting routine estimates the rate using whatever function you have
> chosen to do the fitting. TC is then 1/rate. That is pretty
> non-controversial. The TC error is trickier. The same code that
> estimates the rate also estimates the error to the rate using a
> "bootstrap" method (as of version 1.0.9). Specifically, if you have n
> data points (each x, y), then the program repeatedly (niter times) chooses
> n points out of the n but with repeats allowed. Each of those gives a
> fit, so we end up with a distribution of rates, and the rate error is
> estimated to be the standard deviation of that distribution divided by the
> sqrt(niter-1). Then from that estimate of the rate error you get an
> estimate of the TC error by:
>
> TCerror = 0.5 * (1.0/(rate-rateError) - 1.0/(rate+rateError))
>
> All in all this is slightly dubious. I would trust the TC but not so much
> the TC error. I guess a Bayesian analysis might be better.
>
> Wayne
>
> On Fri, 24 Feb 2006, Karthik Venkatesh Rajasekar wrote:
>
> > Hello!
> >
> > I have tried to determine the T1 nd T2 using the Rates analysis function in
> > CCPN. Can someone tell me what TC and TC error is.
> >
> > karthik
> >
>
|