public static Dictionary <string, List <string> > GetPeptideCompositions(double maxMass)
{
Dictionary <string, List <string> > result = new Dictionary <string, List <string> >();
double mg = glycine.MonoIsotopicMass;
int maxN = (int)((maxMass - Molecule.massWater) / mg);
string aas = StandardSingleLetterAas;
double[] masses = AaMonoMasses;
NumUtils.GetPartitions(maxN, 21, i1 => {
double m1 = Molecule.massWater;
for (int i = 0; i < i1.Length; i++)
{
if (i < 20)
{
m1 += i1[i] * masses[aas[i]];
}
}
return(m1 <= maxMass);
}, i2 => {
string seq = GetSequence(i2, aas);
Molecule m = GetPeptideMolecule(seq);
string formula = m.GetEmpiricalFormula();
if (!result.ContainsKey(formula))
{
result.Add(formula, new List <string>());
}
result[formula].Add(seq);
});
return(result);
}
private static void Partition(TmpPartitionNew x, int len, double maxMass, IList <double> masses, string aas,
ISet <string> result)
{
if (x.remainder == 0 && x.partition.Count == len)
{
IList <int> part = x.partition;
double m1 = Molecule.massWater;
for (int i = 0; i < part.Count; i++)
{
if (i < 20)
{
m1 += part[i] * masses[aas[i]];
}
}
if (m1 <= maxMass)
{
string seq = GetSequence(part, aas);
Molecule m = GetPeptideMolecule(seq);
string formula = m.GetEmpiricalFormula();
if (!result.Contains(formula))
{
result.Add(formula);
}
}
return;
}
if (x.partition.Count == len)
{
return;
}
for (int i = 0; i <= x.remainder; i++)
{
TmpPartitionNew w = x.Add(i, masses, aas);
if (w.mass > maxMass)
{
break;
}
Partition(w, len, maxMass, masses, aas, result);
}
}
