public void TestPPMConversion(double massToConvert, double currentMz, double expectedPPM)
{
var convertedPPM = PeptideMassCalculator.MassToPPM(massToConvert, currentMz);
var reconvertedMass = PeptideMassCalculator.PPMToMass(convertedPPM, currentMz);
Console.WriteLine("DelM of {0} Da converts to {1:F5} ppm at {2:F5} m/z ", massToConvert, convertedPPM, currentMz);
Assert.AreEqual(expectedPPM, convertedPPM, 0.0001, "PPM Conversion error");
Assert.AreEqual(massToConvert, reconvertedMass, 1E-05, "Da to PPM to Da round trip error");
}
private static string GetCorrectedMassErrorPPM(PSM psm, out int intIsotopeError)
{
const double MASS_C13 = 1.00335483;
double dblMassErrorPPM = 0;
intIsotopeError = 0;
if (double.TryParse(psm.MassErrorDa, out var dblDelM))
{
// Examine dblDelM to determine which isotope was chosen
if (dblDelM >= -0.5)
{
// This is the typical case
while (dblDelM > 0.5)
{
dblDelM -= MASS_C13;
intIsotopeError += 1;
}
}
else
{
// This happens less often; but we'll still account for it
// In this case, intCorrectionCount will be negative
while (dblDelM < -0.5)
{
dblDelM += MASS_C13;
intIsotopeError -= 1;
}
}
dblMassErrorPPM = PeptideMassCalculator.MassToPPM(dblDelM, psm.PrecursorNeutralMass);
}
return(dblMassErrorPPM.ToString("0.0000"));
}