On 24/01/11 18:56, Hoa Quynh Do wrote:
> Hello Ccpnmr users,
> 
> I tried to look for the answers of the below questions in the ccpnmr archive,
> but still can not find what I need. It could be that I don't have the correct
> key word. If there is any repeat, I am so sorry for that.
> 
> My first question regards to the method for calculating the peak volumn.
> After doing assignment, in the Peak Table (under Peak menu) I have the Fit
> Method column is blank and Vol. Method contains only option named "box sum".
> Would you explain how the "Fit Method" work here?
> I guess the Vol. Method is similar to Integration Method of Sparky (???). "Box
> sum" is selection of Vol. Method in Ccpnmr. Is there any advantage of using this
> method in stead of Gaussian fit or Lorentzian fit?
> 
> My second question is the "sequence number code" when doing assignment, can I
> remove it? If possible, could you show me how to do that?
> 
> Thank you very much for your help in advance.
> 
> Best regards,
> Hoa
> 
> 
> ------------------------
> Hoa Quynh Do, PhD Candidate
> 
> NRW- Research School BioStruct
> Heinrich-Heine University of Düsseldorf
> 
> Research Center Jülich GmbH
> Institute of Structural Biology and Biophysics (ISB)
> ISB-3: Structural Biochemistry
> 
> D-52425 Jülich, Germany
> Phone: 0049-2461-61-8069
> Email: q.h.do@fz-jülich.de
> 
> 
> ----------------------------------------------------------------
> This message was sent using IMP, the Internet Messaging Program.

Hi Hoa,

this is what wayne wrote some time ago:

The default method (box sum) just sums a certain number of points around
the peak position, as determined by the Peak --> Peak Finding dialog in
the Spectrum Widths tab in the Boxwidth column (which is in points, not
ppm).  The "truncated box sum" makes an attempt to figure out whether the
peak has ended inside the box (so turned back up again).  The "parabolic
fit" uses the peak position and +- 1 to try and fit a parabola and then
uses those parameters to fit a Gaussian and so get an estimate that way.
That is sensitive to noise.  None of these methods is particularly good,
and it is on the TODO list to do better.

There are many more mails on this topic in the archives.


Concerning you second question, you just need to do the peak typing and
not the complete assignment. Therefore you just need to use the "set
type" button which is the second from left in the assignment dialog. If
you already assigned it, use the "Deassign Resonance" dialog.

Cheers, justin

-- 
Justin Lecher
Institute of Complex Systems
ICS-6 Structural Biochemistry
Research Centre Juelich
52425 Juelich, Germany
phone: +49 2461 61 2117