-inf (divide-by-zero) in BaseStar::CalculateMassLossRateWolfRayetTemperatureCorrectionSander2023() #1255
Description
Running COMPAS with:
./compas -n1 --minimum-secondary-mass 5
results in -inf in BaseStar::CalculateMassLossRateWolfRayetTemperatureCorrectionSander2023() in the following statment:
double logMdotUncorrected = log10(p_Mdot); // uncorrected mass-loss rate
because the parameter p_Mdot = 0.0
double BaseStar::CalculateMassLossRateWolfRayetTemperatureCorrectionSander2023(const double p_Mdot) const {
const double teffRef = 141.0E3; // reference effective temperature in Kelvin
const double teffMin = 100.0E3; // minimum effective temperature in Kelvin to apply correction
double teff = m_Temperature * TSOL; // get effective temperature in Kelvin
double logMdotUncorrected = log10(p_Mdot); // uncorrected mass-loss rate
double logMdotCorrected = 0.0;
// Only apply to sufficiently hot stars
if (utils::Compare(teff, teffMin) > 0) {
logMdotCorrected = logMdotUncorrected - 6.0 * log10(teff / teffRef);
}
else {
logMdotCorrected = logMdotUncorrected;
}
return PPOW(10.0, logMdotCorrected);
}
The naive solution is to add the following sanity check as the first line of the function:
if (p_Mdot <= 0.0) return 0.0; // don't use utils::Compare() here
so we just return a mass loss rate of 0.0 if the rate passed in p_Mdot is 0.0
p_Mdot can be passed as 0.0 from HeMS::CalculateMassLossRateMerritt2024() when CalculateMassLossRateWolfRayetSanderVink2020() is called with p_Mu < 1.0 (as it is in HeMS::CalculateMassLossRateMerritt2024()) (this is the case that caused the failure that prompted opening of this issue).
There may be other ways for the problem to manifest
@jmerritt1, @SimonStevenson, can you confirm that the suggestion above is the best solution?
To Reproduce
Run COMPAS with:
./compas -n1 --minimum-secondary-mass 5
Expected behavior
Production code does not cause -inf
**Versioning
- OS: Ubuntu 22.04
- COMPAS v03.07.01