public static IEnumerable <LCIMSMSFeature> FindDriftTimePeaks(Peak driftProfilePeak, LCIMSMSFeature lcimsmsFeature, double averageTOFLength, double framePressure)
{
var imsmsFeatureList = lcimsmsFeature.IMSMSFeatureList;
var sortByScanLCQuery = from imsmsFeature in imsmsFeatureList
orderby imsmsFeature.ScanLC
select imsmsFeature;
var globalIMSScanMinimum = double.MaxValue;
var globalIMSScanMaximum = double.MinValue;
// Grab all of the intensity values for each IMS-MS Feature and find the global minimum and maximum Drift Times
foreach (var imsmsFeature in sortByScanLCQuery)
{
imsmsFeature.GetMinAndMaxIMSScan(out var localIMSScanMinimum, out var localIMSScanMaximum);
if (localIMSScanMinimum < globalIMSScanMinimum)
{
globalIMSScanMinimum = localIMSScanMinimum;
}
if (localIMSScanMaximum > globalIMSScanMaximum)
{
globalIMSScanMaximum = localIMSScanMaximum;
}
}
var smoothedDriftProfilePeak = PeakUtil.KDESmooth(driftProfilePeak, Settings.SmoothingStDev); // TODO: Find a good value. 0.15? Less smooth = more conformations!
var smoothedDriftProfileInterpolation = PeakUtil.GetLinearInterpolationMethod(smoothedDriftProfilePeak);
var xyPairList = new List <XYPair>();
var peakList = new List <Peak>();
var previousIntensity = double.MinValue;
var movingUp = true;
// lcimsmsFeature.GetMinAndMaxScanLC(out var minScanLC, out var maxScanLC);
var minimumIntensityToConsider = smoothedDriftProfilePeak.GetMaximumYValue() * 0.05;
//DisplayPeakXYData(smoothedDriftProfilePeak);
//Console.WriteLine("Global IMS Scan Min = " + globalIMSScanMinimum + "\tGlobal IMS Scan Max = " + globalIMSScanMaximum);
for (var i = globalIMSScanMinimum; i <= globalIMSScanMaximum; i += 1)
{
var imsScan = i;
var intensity = smoothedDriftProfileInterpolation.Interpolate(imsScan);
if (intensity > minimumIntensityToConsider)
{
//Console.WriteLine(imsScan + "\t" + intensity + "\t" + movingUp);
if (intensity > previousIntensity)
{
// End of Peak
if (!movingUp && xyPairList.Count > 0)
{
PadXYPairsWithZeros(ref xyPairList, 2);
//xyPairList = PadXYPairsWithZeros(xyPairList, imsScanMinimum, i - DRIFT_TIME_SLICE_WIDTH, 1);
var peak = new Peak(xyPairList);
if (peak.XYPairList.Count >= 7)
{
peakList.Add(peak);
}
// Start over with a new Peak
xyPairList.Clear();
movingUp = true;
}
}
else
{
movingUp = false;
}
var xyPair = new XYPair(imsScan, intensity);
xyPairList.Add(xyPair);
previousIntensity = intensity;
}
else
{
movingUp = false;
previousIntensity = 0;
}
}
// When you get to the end, end the last Peak, but only if it has a non-zero value
if (xyPairList.Any(xyPair => xyPair.YValue > minimumIntensityToConsider))
{
PadXYPairsWithZeros(ref xyPairList, 2);
//xyPairList = PadXYPairsWithZeros(xyPairList, imsScanMinimum, globalIMSScanMaximum, 1);
var lastPeak = new Peak(xyPairList);
if (lastPeak.XYPairList.Count >= 7)
{
peakList.Add(lastPeak);
}
}
// var resolvingPower = GetResolvingPower(lcimsmsFeature.Charge);
var newLCIMSMSFeatureList = new List <LCIMSMSFeature>();
foreach (var peak in peakList)
{
var repIMSScan = peak.GetQuadraticFit();
// TODO: Fix this
//double theoreticalFWHM = driftTime / resolvingPower;
double theoreticalFWHM = 3;
peak.GetMinAndMaxXValues(out var minimumXValue, out var maximumXValue);
const int numPoints = 100;
var normalDistributionXYPairList = PeakUtil.CreateTheoreticalGaussianPeak(repIMSScan, theoreticalFWHM, numPoints);
PadXYPairsWithZeros(ref normalDistributionXYPairList, 5);
var normalDistributionPeak = new Peak(normalDistributionXYPairList);
var peakInterpolation = PeakUtil.GetLinearInterpolationMethod(peak);
var fitScore = PeakUtil.CalculatePeakFit(peak, normalDistributionPeak, 0);
// Create a new LC-IMS-MS Feature
var newLCIMSMSFeature = new LCIMSMSFeature(lcimsmsFeature.Charge)
{
OriginalIndex = lcimsmsFeature.OriginalIndex,
IMSScore = (float)fitScore,
AbundanceMaxRaw = Math.Round(peak.GetMaximumYValue()),
// Using Math.Floor instaed of Math.Round because I used to cast this to an int which is esentially Math.Floor.
// The difference is negligible, but OHSU would complain if results were the slightest bit different if the app was re-run on the same dataset.
AbundanceSumRaw = Math.Floor(peakInterpolation.Integrate(peak.GetMaximumXValue())),
DriftTime = ConvertIMSScanToDriftTime(repIMSScan, averageTOFLength, framePressure)
};
// Create new IMS-MS Features by grabbing MS Features in each LC Scan that are in the defined window of the detected drift time
foreach (var imsmsFeature in lcimsmsFeature.IMSMSFeatureList)
{
var msFeatures = imsmsFeature.FindMSFeaturesInScanIMSRange(minimumXValue, maximumXValue).ToList();
if (!msFeatures.Any())
{
continue;
}
var newIMSMSFeature = new IMSMSFeature(imsmsFeature.ScanLC, imsmsFeature.Charge);
newIMSMSFeature.AddMSFeatureList(msFeatures);
newLCIMSMSFeature.AddIMSMSFeature(newIMSMSFeature);
}
if (newLCIMSMSFeature.IMSMSFeatureList.Count > 0)
{
newLCIMSMSFeatureList.Add(newLCIMSMSFeature);
/*
* // TODO: Find LC Peaks
* var sortByScanLC = from imsmsFeature in newLCIMSMSFeature.IMSMSFeatureList
* orderby imsmsFeature.ScanLC ascending
* select imsmsFeature;
*
* Console.WriteLine("*************************************************");
* Console.WriteLine("Index = " + index + "\tMass = " + newLCIMSMSFeature.CalculateAverageMass() + "\tDrift = " + driftTime + "\tLC Range = " + sortByScanLC.First().ScanLC + "\t" + sortByScanLC.Last().ScanLC);
*
* List<XYPair> lcXYPairList = new List<XYPair>();
* int scanLC = sortByScanLC.First().ScanLC - 1;
*
* foreach (IMSMSFeature imsmsFeature in sortByScanLC)
* {
* int currentScanLC = imsmsFeature.ScanLC;
*
* for (int i = scanLC + 1; i < currentScanLC; i++)
* {
* XYPair zeroValue = new XYPair(i, 0);
* lcXYPairList.Add(zeroValue);
* Console.Write("0\t");
* }
*
* XYPair xyPair = new XYPair(currentScanLC, imsmsFeature.GetIntensity());
* lcXYPairList.Add(xyPair);
*
* scanLC = currentScanLC;
*
* Console.Write(imsmsFeature.GetIntensity() + "\t");
* }
* Console.WriteLine("");
* Console.WriteLine("*************************************************");
*/
// TODO: Calculate LC Score
}
else
{
//Console.WriteLine("$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ FOUND EMPTY $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$");
// TODO: Figure out why this actually happens. I believe that this SHOULD NOT happen. Below is a hack to return a conformation even if this happens
// It actually looks like most of these occurences are due to large gaps in the drift time, which cause a small peak to be found in the gap which has no members.
//Console.WriteLine("**********************************************************************");
//Console.WriteLine("Detected Drift Time = " + driftTime + "\tLow = " + lowDriftTime + "\tHigh = " + highDriftTime);
//lcimsmsFeature.PrintLCAndDriftTimeMap();
//Console.WriteLine("**********************************************************************");
//Console.WriteLine("===============================================================");
//Console.WriteLine("DT = " + driftTime + "\tLow DT = " + lowDriftTime + "\tHigh DT = " + highDriftTime);
//Console.WriteLine("Global Min = " + globalDriftTimeMinimum + "\tGlobal Max = " + globalDriftTimeMaximum);
//peak.PrintPeakToConsole();
//Console.WriteLine("===============================================================");
}
}
// Find the Conformation that has the highest member count and store the value into all conformations of this LC-IMS-MS Feature
if (newLCIMSMSFeatureList.Count > 0)
{
var maxMemberCount = newLCIMSMSFeatureList.Select(feature => feature.GetMemberCount()).Max();
foreach (var feature in newLCIMSMSFeatureList)
{
feature.MaxMemberCount = maxMemberCount;
}
}
return(newLCIMSMSFeatureList);
}
/// <summary>
/// Executes the cross-link search for LC-IMS-TOF data.
/// </summary>
/// <param name="settings">Settings object to control parameters for cross-linking.</param>
/// <param name="proteinSequenceEnumerable">IEnumerable of protein sequences, as a .NET Bio ISequence object.</param>
/// <param name="featureList">List of LC-IMS-MS Features, as LcImsMsFeature.</param>
/// <param name="peakList">List of Isotopic Peaks, as IsotopicPeak.</param>
/// <returns>An enumerable of CrossLinkResult objects.</returns>
public static IList <CrossLinkResult> Execute(
CrossLinkSettings settings,
IEnumerable <ISequence> proteinSequenceEnumerable,
List <LcImsMsFeature> featureList,
List <IsotopicPeak> peakList)
{
var massToleranceBase = settings.MassTolerance;
var maxMissedCleavages = settings.MaxMissedCleavages;
var digestionRule = settings.TrypticType;
CrossLinkUtil.StaticDeltaMass = settings.StaticDeltaMass;
CrossLinkUtil.UseC13 = settings.UseC13;
CrossLinkUtil.UseN15 = settings.UseN15;
Console.WriteLine();
Console.WriteLine("Mass Tolerance: " + massToleranceBase + " ppm");
Console.WriteLine("Max missed cleavages: " + maxMissedCleavages);
Console.WriteLine("Digestion rule: " + settings.TrypticType);
Console.WriteLine("Delta mass uses C13: " + settings.UseC13);
Console.WriteLine("Delta mass uses N15: " + settings.UseN15);
Console.WriteLine("Static delta mass addon: " + settings.StaticDeltaMass + " Da");
// Used for finding Isotopic Profiles in the data
var msFeatureFinder = new BasicTFF();
var crossLinkList = new List <CrossLink>();
var lastProgress = DateTime.UtcNow;
var proteinsProcessed = 0;
// Create CrossLink objects from all of the protein sequences
foreach (var proteinSequence in proteinSequenceEnumerable)
{
var proteinSequenceString = new string(proteinSequence.Select((a => (char)a)).ToArray());
var proteinId = proteinSequence.ID;
// Get a List of Peptides from the Protein Sequence
var peptideList = SequenceUtil.DigestProtein(proteinSequenceString, digestionRule, maxMissedCleavages);
// Find all possible cross links from the peptide list
var crossLinkEnumerable = CrossLinkUtil.GenerateTheoreticalCrossLinks(peptideList, proteinSequenceString, proteinId);
crossLinkList.AddRange(crossLinkEnumerable);
proteinsProcessed++;
if (DateTime.UtcNow.Subtract(lastProgress).TotalSeconds >= 15)
{
lastProgress = DateTime.UtcNow;
Console.WriteLine("Creating cross linked peptide list; " + proteinsProcessed + " proteins processed");
}
}
Console.WriteLine("Sorting cross-linked peptides");
// Sort the CrossLinks by mass so that the results are ordered in a friendly way
IEnumerable <CrossLink> orderedCrossLinkEnumerable = crossLinkList.OrderBy(x => x.Mass);
// Sort Feature by mass so we can use binary search
featureList = featureList.OrderBy(x => x.MassMonoisotopic).ToList();
// Set up a Feature Comparer and Peak Comparer to use for binary search later on
var featureComparer = new AnonymousComparer <LcImsMsFeature>((x, y) => x.MassMonoisotopic.CompareTo(y.MassMonoisotopic));
var peakComparer = new AnonymousComparer <IsotopicPeak>((x, y) => x.ScanLc != y.ScanLc ? x.ScanLc.CompareTo(y.ScanLc) : x.ScanIms != y.ScanIms ? x.ScanIms.CompareTo(y.ScanIms) : x.Mz.CompareTo(y.Mz));
// Sort the Isotopic Peaks by LC Scan, IMS Scan, and m/z to set them up for binary search later on
peakList.Sort(peakComparer);
var crossLinkResultList = new List <CrossLinkResult>();
var totalCandidatePeptides = crossLinkList.Count;
Console.WriteLine("Searching isotopic data vs. " + totalCandidatePeptides.ToString("#,##0") + " candidate cross-linked peptides");
lastProgress = DateTime.UtcNow;
var crosslinkCandidatesProcessed = 0;
// Search the data for the existence of cross-links
foreach (var crossLink in orderedCrossLinkEnumerable)
{
// Calculate mass tolerance to use for binary search
var massTolerance = massToleranceBase * crossLink.Mass / GeneralConstants.PPM_DIVISOR;
var lowFeature = new LcImsMsFeature {
MassMonoisotopic = crossLink.Mass - massTolerance
};
var highFeature = new LcImsMsFeature {
MassMonoisotopic = crossLink.Mass + massTolerance
};
var lowFeaturePosition = featureList.BinarySearch(lowFeature, featureComparer);
var highFeaturePosition = featureList.BinarySearch(highFeature, featureComparer);
lowFeaturePosition = lowFeaturePosition < 0 ? ~lowFeaturePosition : lowFeaturePosition;
highFeaturePosition = highFeaturePosition < 0 ? ~highFeaturePosition : highFeaturePosition;
// Iterate over all LC-IMS-MS Features that match the Unmodified cross-link mass
for (var i = lowFeaturePosition; i < highFeaturePosition; i++)
{
var feature = featureList[i];
// Search for a mass shift in each of the LC Scans the unmodified cross-link mass was found
for (var currentScanLc = feature.ScanLcStart; currentScanLc <= feature.ScanLcEnd; currentScanLc++)
{
var crossLinkResult = new CrossLinkResult(crossLink, feature, currentScanLc);
var candidatePeaks = PeakUtil.FindCandidatePeaks(peakList, feature.MzMonoisotopic, currentScanLc, feature.ScanImsRep);
var massShiftList = crossLink.MassShiftList;
var shiftedMassList = new List <double>();
// Calculate the shifted mass values that we want to search for
switch (massShiftList.Count)
{
case 1:
{
var firstNewMass = feature.MassMonoisotopic + massShiftList[0];
shiftedMassList.Add(firstNewMass);
}
break;
case 2:
{
var firstNewMass = feature.MassMonoisotopic + massShiftList[0];
var secondNewMass = feature.MassMonoisotopic + massShiftList[1];
var thirdNewMass = feature.MassMonoisotopic + massShiftList[0] + massShiftList[1];
shiftedMassList.Add(firstNewMass);
shiftedMassList.Add(secondNewMass);
shiftedMassList.Add(thirdNewMass);
}
break;
}
// Search for shifted mass values in Isotopic Peaks
foreach (var shiftedMass in shiftedMassList)
{
var shiftedMz = (shiftedMass / feature.ChargeState) + GeneralConstants.MASS_OF_PROTON;
// Create theoretical Isotopic Peaks that will later form a theoretical Isotopic Profile
var theoreticalPeakList = new List <MSPeak> {
new MSPeak {
XValue = shiftedMz, Height = 1
}
};
for (double k = 1; k < 4; k++)
{
theoreticalPeakList.Add(new MSPeak {
XValue = shiftedMz + (k * 1.003 / feature.ChargeState), Height = (float)(1.0 - (k / 4))
});
theoreticalPeakList.Add(new MSPeak {
XValue = shiftedMz - (k * 1.003 / feature.ChargeState), Height = (float)(1.0 - (k / 4))
});
}
// Sort peaks by m/z
var sortPeaksQuery = from peak in theoreticalPeakList
orderby peak.XValue
select peak;
// Create a theoretical Isotopic Profile for DeconTools to search for
var isotopicProfile = new IsotopicProfile
{
MonoIsotopicMass = shiftedMass,
MonoPeakMZ = shiftedMz,
ChargeState = feature.ChargeState,
Peaklist = sortPeaksQuery.ToList()
};
// Search for the theoretical Isotopic Profile
var foundProfile = msFeatureFinder.FindMSFeature(candidatePeaks, isotopicProfile, massToleranceBase, false);
/*
* It is possible that the set mono pass of the previous theoretical distribution was the right-most peak of the actual distribution
* If so, we should be able to shift the theoretical distribution over to the left and find the actual distribution
*/
if (foundProfile == null)
{
foreach (var msPeak in sortPeaksQuery)
{
msPeak.XValue -= (1.003 / feature.ChargeState);
}
isotopicProfile = new IsotopicProfile
{
MonoIsotopicMass = shiftedMass - 1.003,
MonoPeakMZ = shiftedMz - (1.003 / feature.ChargeState),
ChargeState = feature.ChargeState,
Peaklist = sortPeaksQuery.ToList()
};
foundProfile = msFeatureFinder.FindMSFeature(candidatePeaks, isotopicProfile, massToleranceBase, false);
}
// Add to results, even if we did not find it.
var didFindProfile = foundProfile != null;
crossLinkResult.MassShiftResults.KvpList.Add(new KeyValuePair <double, bool>(shiftedMass, didFindProfile));
}
crossLinkResultList.Add(crossLinkResult);
}
}
crosslinkCandidatesProcessed++;
if (DateTime.UtcNow.Subtract(lastProgress).TotalSeconds >= 10)
{
lastProgress = DateTime.UtcNow;
var percentComplete = crosslinkCandidatesProcessed / (double)totalCandidatePeptides * 100;
Console.WriteLine("Searching isotopic data; " + percentComplete.ToString("0.0") + "% complete");
}
}
return(crossLinkResultList);
}
