public static int CalcProductCharge(double productPrecursorMass,
int precursorCharge,
double[,] productMasses,
IList <IList <ExplicitLoss> > potentialLosses,
double productMz,
double tolerance,
MassType massType,
MassShiftType massShiftType,
out IonType?ionType,
out int?ordinal,
out TransitionLosses losses,
out int massShift)
{
// Get length of fragment ion mass array
int len = productMasses.GetLength(1);
// Check all possible ion types and offsets
double minDelta = double.MaxValue, minDeltaNs = double.MaxValue;
int bestCharge = 0, bestChargeNs = 0;
IonType? bestIonType = null, bestIonTypeNs = null;
int? bestOrdinal = null, bestOrdinalNs = null;
TransitionLosses bestLosses = null, bestLossesNs = null;
int bestMassShift = 0;
// Check to see if it is the precursor
foreach (var lossesTrial in TransitionGroup.CalcTransitionLosses(IonType.precursor, 0, massType, potentialLosses))
{
double productMass = productPrecursorMass - (lossesTrial != null ? lossesTrial.Mass : 0);
int potentialMassShift;
int nearestCharge;
int? charge = CalcProductCharge(productMass, productMz, tolerance, false, precursorCharge,
massShiftType, out potentialMassShift, out nearestCharge);
if (charge.HasValue && charge.Value == precursorCharge)
{
double potentialMz = SequenceMassCalc.GetMZ(productMass, charge.Value) + potentialMassShift;
double delta = Math.Abs(productMz - potentialMz);
if (potentialMassShift == 0 && minDeltaNs > delta)
{
bestChargeNs = charge.Value;
bestIonTypeNs = IonType.precursor;
bestOrdinalNs = len + 1;
bestLossesNs = lossesTrial;
minDeltaNs = delta;
}
else if (potentialMassShift != 0 && minDelta > delta)
{
bestCharge = charge.Value;
bestIonType = IonType.precursor;
bestOrdinal = len + 1;
bestLosses = lossesTrial;
bestMassShift = potentialMassShift;
minDelta = delta;
}
}
}
foreach (IonType type in Transition.ALL_TYPES)
{
// Types have priorities. If moving to a lower priority type, and there is already a
// suitable answer stop looking.
if ((type == Transition.ALL_TYPES[2] || type == Transition.ALL_TYPES[2]) &&
(MatchMz(minDelta, tolerance) || MatchMz(minDeltaNs, tolerance)))
{
break;
}
for (int offset = 0; offset < len; offset++)
{
foreach (var lossesTrial in TransitionGroup.CalcTransitionLosses(type, offset, massType, potentialLosses))
{
// Look for the closest match.
double productMass = productMasses[(int)type, offset];
if (lossesTrial != null)
{
productMass -= lossesTrial.Mass;
}
int potentialMassShift;
int nearestCharge;
int?chargeFound = CalcProductCharge(productMass, productMz, tolerance, false, precursorCharge,
massShiftType, out potentialMassShift, out nearestCharge);
if (chargeFound.HasValue)
{
int charge = chargeFound.Value;
double potentialMz = SequenceMassCalc.GetMZ(productMass, charge) + potentialMassShift;
double delta = Math.Abs(productMz - potentialMz);
if (potentialMassShift == 0 && minDeltaNs > delta)
{
bestChargeNs = charge;
bestIonTypeNs = type;
// The peptide length is 1 longer than the mass array
bestOrdinalNs = Transition.OffsetToOrdinal(type, offset, len + 1);
bestLossesNs = lossesTrial;
minDeltaNs = delta;
}
else if (potentialMassShift != 0 && minDelta > delta)
{
bestCharge = charge;
bestIonType = type;
// The peptide length is 1 longer than the mass array
bestOrdinal = Transition.OffsetToOrdinal(type, offset, len + 1);
bestLosses = lossesTrial;
bestMassShift = potentialMassShift;
minDelta = delta;
}
}
}
}
}
// Pefer no-shift to shift, even if the shift value is closer
if (MatchMz(minDelta, tolerance) && !MatchMz(minDeltaNs, tolerance))
{
ionType = bestIonType;
ordinal = bestOrdinal;
losses = bestLosses;
massShift = bestMassShift;
return(bestCharge);
}
ionType = bestIonTypeNs;
ordinal = bestOrdinalNs;
losses = bestLossesNs;
massShift = 0;
return(bestChargeNs);
}
public static Adduct CalcProductCharge(TypedMass productPrecursorMass,
Adduct precursorCharge,
IList <IonType> acceptedIonTypes,
IonTable <TypedMass> productMasses,
IList <IList <ExplicitLoss> > potentialLosses,
double productMz,
double tolerance,
MassType massType,
MassShiftType massShiftType,
out IonType?ionType,
out int?ordinal,
out TransitionLosses losses,
out int massShift)
{
// Get length of fragment ion mass array
int len = productMasses.GetLength(1);
// Check all possible ion types and offsets
double? minDelta = null;
var bestCharge = Adduct.EMPTY;
IonType? bestIonType = null;
int? bestOrdinal = null;
TransitionLosses bestLosses = null;
int bestMassShift = 0;
// Check to see if it is the precursor
foreach (var lossesTrial in TransitionGroup.CalcTransitionLosses(IonType.precursor, 0, massType, potentialLosses))
{
var productMass = productPrecursorMass - (lossesTrial != null ? lossesTrial.Mass : 0);
int potentialMassShift;
int nearestCharge;
var charge = CalcProductCharge(productMass, productMz, tolerance, false, precursorCharge,
massShiftType, out potentialMassShift, out nearestCharge);
if (Equals(charge, precursorCharge))
{
double potentialMz = SequenceMassCalc.GetMZ(productMass, charge) + potentialMassShift;
double delta = Math.Abs(productMz - potentialMz);
if (CompareIonMatch(delta, lossesTrial, potentialMassShift, minDelta, bestLosses, bestMassShift) < 0)
{
bestCharge = charge;
bestIonType = IonType.precursor;
bestOrdinal = len + 1;
bestLosses = lossesTrial;
bestMassShift = potentialMassShift;
minDelta = delta;
}
}
}
var categoryLast = -1;
foreach (var typeAccepted in GetIonTypes(acceptedIonTypes))
{
var type = typeAccepted.IonType;
var category = typeAccepted.IonCategory;
// Types have priorities. If changing type category, and there is already a
// suitable answer stop looking.
if (category != categoryLast && minDelta.HasValue && MatchMz(minDelta.Value, tolerance))
{
break;
}
categoryLast = category;
for (int offset = 0; offset < len; offset++)
{
foreach (var lossesTrial in TransitionGroup.CalcTransitionLosses(type, offset, massType, potentialLosses))
{
// Look for the closest match.
var productMass = productMasses[type, offset];
if (lossesTrial != null)
{
productMass -= lossesTrial.Mass;
}
int potentialMassShift;
int nearestCharge;
var chargeFound = CalcProductCharge(productMass, productMz, tolerance, false, precursorCharge,
massShiftType, out potentialMassShift, out nearestCharge);
if (!chargeFound.IsEmpty)
{
var charge = chargeFound;
double potentialMz = SequenceMassCalc.GetMZ(productMass, charge) + potentialMassShift;
double delta = Math.Abs(productMz - potentialMz);
if (CompareIonMatch(delta, lossesTrial, potentialMassShift, minDelta, bestLosses, bestMassShift) < 0)
{
bestCharge = charge;
bestIonType = type;
// The peptide length is 1 longer than the mass array
bestOrdinal = Transition.OffsetToOrdinal(type, offset, len + 1);
bestLosses = lossesTrial;
bestMassShift = potentialMassShift;
minDelta = delta;
}
}
}
}
}
ionType = bestIonType;
ordinal = bestOrdinal;
losses = bestLosses;
massShift = bestMassShift;
return(bestCharge);
}
