July 27, 2012, midnight by Sonya Alexandrova
Getting Real with Spectra
In “Inferring Peptide from Full Spectrum”, we considered an idealized version of the simplified spectrum in which every cut through a given peptide was produced, so that the spectrum possessed all possible b-ions and y-ions cutting the peptide. In reality, not every cut will be produced in a spectrum, which may also contain errors. As a result, it is difficult or impossible to recover an entire peptide from a single spectrum.
In the more practical case of a mass spectrum, where intensity is plotted against ions' mass-charge ratios, inferring the protein is also greatly complicated by the presence of erratic peaks in the spectrum.
For a weighted alphabet
In this problem, we say that a weighted string
Given: A list
3524.8542 3623.5245 3710.9335 3841.974 3929.00603 3970.0326 4026.05879 4057.0646 4083.08025
How can our question be rephrased in terms of the spectrum graph?