public double PearsonCorrelation(Peak[] spectrum1, Peak[] spectrum2,FilteredProteinMassBinning comparer)
{
var spec1Bar = 0d;
var spec2Bar = 0d;
spectrum1 = GuassianFilter(spectrum1, .5);
spectrum2 = GuassianFilter(spectrum2, .5);
var vectorLength = comparer.GetBinNumber(10000.0);
spec1Bar = spectrum1.Sum(x => x.Intensity)/vectorLength;
spec2Bar = spectrum1.Sum(y => y.Intensity)/vectorLength;
var intensityVector1 = ConvertToFullIntensityVector(spectrum1, vectorLength, comparer);
var intensityVector2 = ConvertToFullIntensityVector(spectrum2, vectorLength, comparer);
var cov = 0.0;
var s1 = 0.0;
var s2 = 0.0;
for (var i = 0; i < vectorLength; i++)
{
var d1 = intensityVector1[i] - spec1Bar;
var d2 = intensityVector2[i] - spec2Bar;
cov += d1*d2;
s1 += d1*d1;
s2 += d2*d2;
}
if (s1 <= 0 || s2 <= 0) return 0;
return cov < 0 ? 0f : cov/Math.Sqrt(s1*s2);
}
public double RootMeanSquareDeviation(Peak[] spectrum1, Peak[] spectrum2, FilteredProteinMassBinning comparer)
{
spectrum1 = GuassianFilter(spectrum1, .5);
spectrum2 = GuassianFilter(spectrum2, .5);
var vectorLength = comparer.GetBinNumber(10000.0);
var intensityVector1 = ConvertToFullIntensityVector(spectrum1, vectorLength, comparer);
var intensityVector2 = ConvertToFullIntensityVector(spectrum2, vectorLength, comparer);
var mean1 = spectrum1.Sum(p => p.Intensity)/spectrum1.Length;
var mean2 = spectrum1.Sum(p => p.Intensity)/spectrum2.Length;
var sum = 0d;
for (int i = 0; i < vectorLength; i++)
{
var diff = intensityVector1[i] - intensityVector2[i];
sum += diff*diff;
}
return Math.Sqrt(sum/vectorLength);
}
public static double GetRefIntensity(Peak[] peaks)
{
return peaks.Sum(p => p.Intensity);
}
public double GetRegressionIntercept(Peak[] spectrum, double b)
{
var n = spectrum.Length;
var sumX = spectrum.Sum(p => p.Mz);
var sumY = spectrum.Sum(p => p.Intensity);
return (sumY - b*sumX)/n;
}
public double GetRegressionSlope(Peak[] spectrum)
{
var n = spectrum.Length;
var sumXY = spectrum.Sum(p => p.Mz*p.Intensity);
var sumX = spectrum.Sum(p => p.Mz);
var sumY = spectrum.Sum(p => p.Intensity);
var sumXSquared = spectrum.Sum(p => p.Mz*p.Mz);
return (n*sumXY - sumX*sumY)/(n*sumXSquared - sumX*sumX);
}
