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SteinScottImproveScore Class Reference
[Spectrum Comparison]

Similarity score based of Stein & Scott. More...

#include <OpenMS/COMPARISON/SPECTRA/SteinScottImproveScore.h>

Inheritance diagram for SteinScottImproveScore:
PeakSpectrumCompareFunctor DefaultParamHandler

List of all members.

Public Member Functions

 SteinScottImproveScore ()
 default constructor
 SteinScottImproveScore (const SteinScottImproveScore &source)
 copy constructor
virtual ~SteinScottImproveScore ()
 destructor
SteinScottImproveScoreoperator= (const SteinScottImproveScore &source)
 assignment operator
double operator() (const PeakSpectrum &spec1, const PeakSpectrum &spec2) const
 Similarity pairwise score.
double operator() (const PeakSpectrum &spec) const
 Similarity pairwise score itself.

Static Public Member Functions

static PeakSpectrumCompareFunctorcreate ()
static const String getProductName ()

Detailed Description

Similarity score based of Stein & Scott.

This is a pairwise based score function. The spectrum contains peaks, and each peak can be defined by two values (mz and the intensity). The score function takes the sum of the product of the peak intensities from Spectrum 1 and Spectrum 2, only if the mz-ratio distance between the two spectrums is smaller than a given window size. In the default status, the window size is (accuracy of the mass spectrometer). This sum is normalised by dividing it with a distance function. sqrt(sum of the Intensity of square Spectrum1 sum of the Intensity of square Spectrum2). This is all based on SteinScott score. To distinguish the close from the distant spectra an additional term is calculated. It denotes the expected value of both Spectrums under the random placement of all peaks, within the given mass-to-charge range. The probability that two peaks with randomized intensity values lie within two epsilon of each other is a constant. This constant is proportional to epsilon. So the additional term is the sum over all peaks of Spectrum 1 and Spectrum 2 of the products of their intensities multiplied with the constant.

The details of the score can be found in: Signal Maps for Mass Spectrometry-based Comparative Proteomics Amol Prakash, Parag Mallick , Jeffrey Whiteaker, Heidi Zhang, Amanda Paulovich, Mark Flory, Hookeun Lee, Ruedi Aebersold, and Benno Schwikowski

Parameters of this class are:

NameTypeDefaultRestrictionsDescription
tolerance float0.2  defines the absolute error of the mass spectrometer
threshold float0.2  if the calculated score is smaller than the threshold, a zero is given back

Note:

Constructor & Destructor Documentation

default constructor

copy constructor

virtual ~SteinScottImproveScore (  )  [virtual]

destructor


Member Function Documentation

static PeakSpectrumCompareFunctor* create (  )  [inline, static]
static const String getProductName (  )  [inline, static]

Reimplemented from PeakSpectrumCompareFunctor.

double operator() ( const PeakSpectrum spec1,
const PeakSpectrum spec2 
) const [virtual]

Similarity pairwise score.

This function return the similarity score of two Spectrums based on SteinScott.

Implements PeakSpectrumCompareFunctor.

double operator() ( const PeakSpectrum spec  )  const [virtual]

Similarity pairwise score itself.

This function return the similarity score of itself based on SteinScott.

Implements PeakSpectrumCompareFunctor.

SteinScottImproveScore& operator= ( const SteinScottImproveScore source  ) 

assignment operator


OpenMS / TOPP release 1.10.0 Documentation generated on Thu Mar 7 2013 09:42:51 using doxygen 1.7.1