Example #1
0
        public void GetRatioBasedOnTopPeaks(IsotopicProfile iso1, IsotopicProfile iso2,
                                            IsotopicProfile theorIso1, IsotopicProfile theorIso2, double backgroundIntensity, int numPeaks,
                                            out double ratio, out double ratioContribForIso1, out double ratioContribForIso2)
        {
            //Find top n peaks of the theor profile.  Reference them by their peak index so that they can be looked up in the experimental.
            //List<int> sortedTheorIso1Indexes = getIndexValsOfTopPeaks(theorIso1);
            //List<int> sortedTheorIso2Indexes = getIndexValsOfTopPeaks(theorIso2);

            IList <Peak> topTheorIso1Peaks = GetTopPeaks(theorIso1, numPeaks);
            IList <Peak> topTheorIso2Peaks = GetTopPeaks(theorIso2, numPeaks);

            //get the top n peaks of the experimental profile, based on peaks of the theor profile
            //adjust intensity (subtract background intensity)
            var topIso1Peaks = GetTopPeaksBasedOnTheor(iso1, topTheorIso1Peaks, MSToleranceInPPM);
            var topIso2Peaks = GetTopPeaksBasedOnTheor(iso2, topTheorIso2Peaks, MSToleranceInPPM);

            //Since the number of top experimental iso peaks may be less than the number of top theor iso peaks,
            //we have to filter and ensure that they have the same peak numbers, so that the correction factor
            // (applied below) is properly applied.   HOWEVER,  this may induce some differences between runs
            var filteredTopTheorIso1Peaks = GetTopPeaksBasedOnTheor(theorIso1, topIso1Peaks, MSToleranceInPPM);
            var filteredTopTheorIso2Peaks = GetTopPeaksBasedOnTheor(theorIso2, topIso2Peaks, MSToleranceInPPM);

            var summedTopIso1PeakIntensities = PeakUtilities.GetSumOfIntensities(topIso1Peaks, backgroundIntensity);
            var summedTopIso2PeakIntensities = PeakUtilities.GetSumOfIntensities(topIso2Peaks, backgroundIntensity);

            //Console.WriteLine(backgroundIntensity);

            //need to find out the contribution of the top n peaks to the overall isotopic envelope.  Base this on the theor profile
            double summedTheorIso1Intensities = filteredTopTheorIso1Peaks.Sum(p => (p.Height));
            double summedTheorIso2Intensities = filteredTopTheorIso2Peaks.Sum(p => (p.Height));

            var fractionTheor1 = summedTheorIso1Intensities / theorIso1.Peaklist.Sum(p => p.Height);
            var fractionTheor2 = summedTheorIso2Intensities / theorIso2.Peaklist.Sum(p => p.Height);

            //use the above ratio to correct the intensities based on how much the top n peaks contribute to the profile.
            var correctedIso1SummedIntensity = summedTopIso1PeakIntensities / fractionTheor1;
            var correctedIso2SummedIntensity = summedTopIso2PeakIntensities / fractionTheor2;

            var summedAllIsos1PeakIntensities = iso1.Peaklist.Sum(p => (p.Height - backgroundIntensity));
            var summedAllIsos2PeakIntensities = iso2.Peaklist.Sum(p => (p.Height - backgroundIntensity));

            switch (RatioType)
            {
            case RatioType.ISO1_OVER_ISO2:
                ratio = correctedIso1SummedIntensity / correctedIso2SummedIntensity;
                break;

            case RatioType.ISO2_OVER_ISO1:
                ratio = correctedIso2SummedIntensity / correctedIso1SummedIntensity;
                break;

            default:
                ratio = correctedIso1SummedIntensity / correctedIso2SummedIntensity;
                break;
            }

            ratioContribForIso1 = summedTopIso1PeakIntensities / summedAllIsos1PeakIntensities * 1 / fractionTheor1;   //we expect a value of '1'
            ratioContribForIso2 = summedTopIso2PeakIntensities / summedAllIsos2PeakIntensities * 1 / fractionTheor2;
        }