[CSC 335] Check on Peaks

[Andrew J. Pounds]

Gentlemen -- in class today Bryan asked me to check on my peak tops 
because they were an order or magnitude higher than the ones you were 
getting.   He is correct -- when I added the code to display the peak 
tops I copied a line in my code that included a Fortran edit descriptor 
"multiplier" that has to be there for the items displayed in scientific 
notation to show up properly - but it was not needed for the things 
shown in in floating format.

So for comparison all of my numbers in the "Top" column shown on the 
handout should be divided by 10.

Also, regarding the "extra peak" that some of you are finding, I think 
it is related to when and how you are filtering.  I replotted my 
filtered peaks and the baseline.  They are shown below.

nmr

In my results the peak at -3.6 is getting picked up as one big peak.  
Based on the plot, this makes sense because the minimum between the two 
peaks on the left is above the baseline.  If for any reason your 
filtering pulls that minimum down below the baseline then you should get 
another peak.

If you are curious, my order of operations is...

 1. Fix TMS location
 2. Adjust the baseline
 3. Filter
 4. Fit the spline
 5. Find the peaks
 6. Locate peak max values
 7. Integrate peaks
 8. Calculate hydrogens


If you are curious about your own code then I really encourage you to 
plot things in gnuplot.  You can create a datafile for checking your 
baseline.  If the baseling were 1400 then I would create a datafile with 
two points.

-5 1400
0 1400

If you plot this with your spectrum then you should see where your peaks 
are getting selected.  In the file above, which was after fixing the 
baseline and filtering, I set my file up as....

-5 0
0 0


-- 
Andrew J. Pounds, Ph.D.  (pounds_aj at mercer.edu)
Professor of Chemistry and Computer Science
Mercer University,  Macon, GA 31207   (478) 301-5627
http://faculty.mercer.edu/pounds_aj

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