Hello,
Ah, this is a good point. So the intensA and intensB in that formula are
the height/volume, but just looking at the code now, the noise levels
(noiseSat and noiseRef) are determined from a function called
getSpectrumNoise(), and that returns what in effect is an intensity, not a
volume, no matter what intensity type you have selected in that dialog.
So in the volume case the noise/intens ratios are not dimensionless and
that sounds supicious to me (but Tim would have a better idea).
Wayne
On Fri, 15 May 2009, Giacomo Quilici wrote:
> Goodmorning,
>
> I read this discussion and I have just a further question. I used some different software,
> including CCpnmr, for calculating hetNOE because i had some problems whit the estimation of the
> errors.
> I already know that formula, but it's used also when the hetNOE ratio is calculated from
> volumes?
>
> I observed that if I choose volumes for the analysis, whit the same spectra and the same
> peaklist, the values of hetNOE are the same (less than an imperfect form of peak) of the
> intensity one, but the error is one order of magnitude less (1-2/1000 instead 1-2/100).
>
> I just want to know if choosing volumes for the analysis implies that the error is calculated
> substituting intensA and intensB whit volumeA and volumeB.
>
> best regards
>
> Giacomo Quilici
>
>
>
>
>
> > Date: Fri, 15 May 2009 10:53:06 +0100
> > From: [log in to unmask]
> > Subject: Re: Heteronuclear NOE
> > To: [log in to unmask]
> >
> > Hello,
> >
> > Tim says that the error is calculated in the code as:
> >
> > value = float(intensA)/intensB
> > error = abs(value) * sqrt((noiseSat/intensA)**2 + (noiseRef/intensB)**2)
> >
> > And he adds:
> >
> > "There is no reference as such, as this is pretty standard maths; possibly
> > a relevent NMR publication could be found. If anything, the suggestion
> > came from the comminity, not from a paper."
> >
> > Wayne
> >
> > On Thu, 14 May 2009, Paul Leonard wrote:
> >
> > > Hi
> > >
> > > I have been using the heteronuclear NOE analysis software which has all
> > > worked really nicely. However I am unsure how to reference this correctly
> > > in a publication and am also interested in understanding how the errors
> > > have been calculated. Could you tell me the appropriate reference?
> > >
> > > Thank-you
> > >
> > > Paul
> > >
> > >
> > > Department of Biochemistry
> > > UMDNJ-Robert Wood Johnson Medical School
> > > Center for Advanced Biotechnology and Medicine
> > > 679 Hoes Lane
> > > Piscataway, New Jersey 08854-5627
> > >
> > > Phone: (732) 235-4206
> > > Email: [log in to unmask]
> > >
>
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