예제 #1
0
        public IsotopeDistInfo(MassDistribution massDistribution,
                               TypedMass monoisotopicMass,
                               Adduct adduct,
                               Func <double, double> calcFilterWindow,
                               double massResolution,
                               double minimumAbundance)
        {
            _monoisotopicMass = monoisotopicMass;
            _adduct           = adduct.Unlabeled; // Don't reapply explicit isotope labels

            // Get peak center of mass values for the given resolution
            var q1FilterValues = MassDistribution.NewInstance(massDistribution, massResolution, 0).Keys.ToList();
            // Find the monoisotopic m/z and make sure it is exactly the expected number
            double monoMz        = _adduct.MzFromNeutralMass(_monoisotopicMass);
            double monoMzDist    = monoMz;
            int    monoMassIndex = 0;

            for (int i = 0; i < q1FilterValues.Count; i++)
            {
                double peakCenterMz = q1FilterValues[i];
                double filterWindow = calcFilterWindow(peakCenterMz);
                double startMz      = peakCenterMz - filterWindow / 2;
                double endMz        = startMz + filterWindow;
                if (startMz < monoMz && monoMz < endMz)
                {
                    monoMzDist        = q1FilterValues[i];
                    q1FilterValues[i] = monoMz;
                    monoMassIndex     = i;
                    break;
                }
            }
            // Insert a M-1 peak, even if it is not expected in the isotope mass distribution
            if (monoMassIndex == 0 && q1FilterValues.Count > 1)
            {
                // Use the delta from the original distribution monoMz to the next peak
                q1FilterValues.Insert(0, monoMz + monoMzDist - q1FilterValues[1]);
                monoMassIndex++;
            }

            if (!q1FilterValues.Any())
            {
                // This should never happen, but just in case it does happen, we safely exit the constructor
                ExpectedPeaks = ImmutableList.Singleton(new MzRankProportion(monoMz, 0, 1.0f));
                MonoMassIndex = BaseMassIndex = 0;
                return;
            }

            var signedQ1FilterValues = q1FilterValues.Select(q => new SignedMz(q, adduct.AdductCharge < 0)).ToList();

            // Use the filtering algorithm that will be used on real data to determine the
            // expected proportions of the mass distribution that will end up filtered into
            // peaks
            // CONSIDER: Mass accuracy information is not calculated here
            var key    = new PrecursorTextId(signedQ1FilterValues[monoMassIndex], null, null, ChromExtractor.summed);
            var filter = new SpectrumFilterPair(key, PeptideDocNode.UNKNOWN_COLOR, 0, null, null, false, false);

            filter.AddQ1FilterValues(signedQ1FilterValues, calcFilterWindow);

            var expectedSpectrum = filter.FilterQ1SpectrumList(new[] { new MsDataSpectrum
                                                                       {
                                                                           Mzs = massDistribution.Keys.ToArray(), Intensities = massDistribution.Values.ToArray(), NegativeCharge = (adduct.AdductCharge < 0)
                                                                       } });

            int startIndex = expectedSpectrum.Intensities.IndexOf(inten => inten >= minimumAbundance);

            if (startIndex == -1)
            {
                // This can happen if the amino acid modifications are messed up,
                // and the peptide mass is negative or something.
                ExpectedPeaks = ImmutableList.Singleton(new MzRankProportion(monoMz, 0, 1.0f));
                MonoMassIndex = BaseMassIndex = 0;
                return;
            }
            // Always include the M-1 peak, even if it is expected to have zero intensity
            if (startIndex > monoMassIndex - 1)
            {
                startIndex = monoMassIndex - 1;
            }
            if (startIndex < 0)
            {
                startIndex = 0;
            }
            int endIndex              = expectedSpectrum.Intensities.LastIndexOf(inten => inten >= minimumAbundance) + 1;
            int countPeaks            = endIndex - startIndex;
            var listProportionIndices = new List <KeyValuePair <float, int> >(countPeaks);

            for (int i = 0; i < countPeaks; i++)
            {
                listProportionIndices.Add(new KeyValuePair <float, int>(
                                              expectedSpectrum.Intensities[i + startIndex], i));
            }
            // Sort proportions descending.
            listProportionIndices.Sort((p1, p2) => Comparer.Default.Compare(p2.Key, p1.Key));

            // Set proportions and ranks back in the original locations
            var expectedProportionRanks = new KeyValuePair <float, int> [countPeaks];

            for (int i = 0; i < countPeaks; i++)
            {
                expectedProportionRanks[listProportionIndices[i].Value] =
                    new KeyValuePair <float, int>(listProportionIndices[i].Key, i + 1);
            }

            MonoMassIndex = monoMassIndex - startIndex;

            // Find the base peak and fill in the masses and proportions
            var expectedPeaks = new List <MzRankProportion>();

            for (int i = 0; i < countPeaks; i++)
            {
                float expectedProportion = expectedProportionRanks[i].Key;
                int   rank = expectedProportionRanks[i].Value;
                expectedPeaks.Add(new MzRankProportion(q1FilterValues[i + startIndex], rank, expectedProportion));
                if (expectedProportion > expectedProportionRanks[BaseMassIndex].Key)
                {
                    BaseMassIndex = i;
                }
            }
            ExpectedPeaks = expectedPeaks;
        }
예제 #2
0
        public IsotopeDistInfo(MassDistribution massDistribution,
                               double monoisotopicMass,
                               bool isMassH, // Is monoisotopicMass M+H, or just M as in small molecule use?
                               int charge,
                               Func <double, double> calcFilterWindow,
                               double massResolution,
                               double minimumAbundance)
        {
            _monoisotopicMass = monoisotopicMass;
            _charge           = charge;
            _isMassH          = isMassH;

            // Get peak center of mass values for the given resolution
            var q1FilterValues = MassDistribution.NewInstance(massDistribution, massResolution, 0).Keys.ToList();
            // Find the monoisotopic m/z and make sure it is exactly the expected number
            double monoMz        = isMassH ? SequenceMassCalc.GetMZ(_monoisotopicMass, _charge) : BioMassCalc.CalculateIonMz(_monoisotopicMass, _charge);
            double monoMzDist    = monoMz;
            int    monoMassIndex = 0;

            for (int i = 0; i < q1FilterValues.Count; i++)
            {
                double peakCenterMz = q1FilterValues[i];
                double filterWindow = calcFilterWindow(peakCenterMz);
                double startMz      = peakCenterMz - filterWindow / 2;
                double endMz        = startMz + filterWindow;
                if (startMz < monoMz && monoMz < endMz)
                {
                    monoMzDist        = q1FilterValues[i];
                    q1FilterValues[i] = monoMz;
                    monoMassIndex     = i;
                    break;
                }
            }
            // Insert a M-1 peak, even if it is not expected in the isotope mass distribution
            if (monoMassIndex == 0 && q1FilterValues.Count > 1)
            {
                // Use the delta from the original distribution monoMz to the next peak
                q1FilterValues.Insert(0, monoMz + monoMzDist - q1FilterValues[1]);
                monoMassIndex++;
            }

            if (!q1FilterValues.Any())  // As is small molecule docs with mz values only, no formulas
            {
                return;
            }

            // Use the filtering algorithm that will be used on real data to determine the
            // expected proportions of the mass distribution that will end up filtered into
            // peaks
            // CONSIDER: Mass accuracy information is not calculated here
            var key    = new PrecursorTextId(q1FilterValues[monoMassIndex], null, ChromExtractor.summed);
            var filter = new SpectrumFilterPair(key, PeptideDocNode.UNKNOWN_COLOR, 0, null, null, null, null, 0, false, false);

            filter.AddQ1FilterValues(q1FilterValues, calcFilterWindow);

            var expectedSpectrum = filter.FilterQ1SpectrumList(new[] { new MsDataSpectrum
                                                                       {
                                                                           Mzs = massDistribution.Keys.ToArray(), Intensities = massDistribution.Values.ToArray()
                                                                       } });

            int startIndex = expectedSpectrum.Intensities.IndexOf(inten => inten >= minimumAbundance);

            if (startIndex == -1)
            {
                throw new InvalidOperationException(
                          string.Format(Resources.IsotopeDistInfo_IsotopeDistInfo_Minimum_abundance__0__too_high,
                                        minimumAbundance));
            }
            // Always include the M-1 peak, even if it is expected to have zero intensity
            if (startIndex > monoMassIndex - 1)
            {
                startIndex = monoMassIndex - 1;
            }
            if (startIndex < 0)
            {
                startIndex = 0;
            }
            int endIndex              = expectedSpectrum.Intensities.LastIndexOf(inten => inten >= minimumAbundance) + 1;
            int countPeaks            = endIndex - startIndex;
            var listProportionIndices = new List <KeyValuePair <float, int> >(countPeaks);

            for (int i = 0; i < countPeaks; i++)
            {
                listProportionIndices.Add(new KeyValuePair <float, int>(
                                              expectedSpectrum.Intensities[i + startIndex], i));
            }
            // Sort proportions descending.
            listProportionIndices.Sort((p1, p2) => Comparer.Default.Compare(p2.Key, p1.Key));

            // Set proportions and ranks back in the original locations
            var expectedProportionRanks = new KeyValuePair <float, int> [countPeaks];

            for (int i = 0; i < countPeaks; i++)
            {
                expectedProportionRanks[listProportionIndices[i].Value] =
                    new KeyValuePair <float, int>(listProportionIndices[i].Key, i + 1);
            }

            // TODO: Can this be discarded?
            // MassDistribution = massDistribution;

            MonoMassIndex = monoMassIndex - startIndex;

            // Find the base peak and fill in the masses and proportions
            var expectedPeaks = new List <MzRankProportion>();

            for (int i = 0; i < countPeaks; i++)
            {
                float expectedProportion = expectedProportionRanks[i].Key;
                int   rank = expectedProportionRanks[i].Value;
                expectedPeaks.Add(new MzRankProportion(q1FilterValues[i + startIndex], rank, expectedProportion));
                if (expectedProportion > expectedProportionRanks[BaseMassIndex].Key)
                {
                    BaseMassIndex = i;
                }
            }
            ExpectedPeaks = expectedPeaks;
        }