AddIsotopicCorrection

How does LipidX correct the isotopes?

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What is the output if a peak was recogniced as isotope

If the isopic part of a peak reduces the peak to less than (1), a '-1' is written to show that this peak was a pure isotope according to the given import settings. I the value is greater than (1), the rest of the peak remains since it is most probalbly an overlapping peak with the isotope.

(1) <math>\frac{T}{\sqrt{n}}</math>

where <math>T</math> is the threshold as set in the import and <math>n</math> the scan number. This is the same procedure to remove noise peaks as used in the import routine.

Remarks for the function sumIntensity()

The function sumIntensity() has a special behavior for isotopic corrected values: If there are MasterScan entries to sum up, which all are isotopes (i.e. all intensities are '-1') then those values are just added and will result in <math>n_i\times -1</math> where <math>n_i</math> is the number of the attributes. If there is just one entry whose intensity is greater zero all <math>-1</math> values are threaded as zero and not added to the overall sum. Some examples should make it clear:

<math>-1 + -1 = -2</math>
<math> 0 + -1 = -1</math>
<math> 1 + -1 = 1</math>
<math> 2 + -1 = 2</math>
<math> 2 + 0 = 2</math>