int
gsl_integration_qag (const gsl_function *f,
double a, double b,
double epsabs, double epsrel, size_t limit,
int key,
gsl_integration_workspace * workspace,
double * result, double * abserr)
{
int status ;
gsl_integration_rule * integration_rule = gsl_integration_qk15 ;
if (key < GSL_INTEG_GAUSS15)
{
key = GSL_INTEG_GAUSS15 ;
}
else if (key > GSL_INTEG_GAUSS61)
{
key = GSL_INTEG_GAUSS61 ;
}
switch (key)
{
case GSL_INTEG_GAUSS15:
integration_rule = gsl_integration_qk15 ;
break ;
case GSL_INTEG_GAUSS21:
integration_rule = gsl_integration_qk21 ;
break ;
case GSL_INTEG_GAUSS31:
integration_rule = gsl_integration_qk31 ;
break ;
case GSL_INTEG_GAUSS41:
integration_rule = gsl_integration_qk41 ;
break ;
case GSL_INTEG_GAUSS51:
integration_rule = gsl_integration_qk51 ;
break ;
case GSL_INTEG_GAUSS61:
integration_rule = gsl_integration_qk61 ;
break ;
default:
GSL_ERROR("value of key does specify a known integration rule",
GSL_EINVAL) ;
}
status = qag (f, a, b, epsabs, epsrel, limit,
workspace,
result, abserr,
integration_rule) ;
return status ;
}
Real calorimeterLSF::getLSF (Real deltaE1, Real deltaE2)
{
// Real answer = qags (deltaE2, deltaE1);
// Real answer = qng (deltaE2, deltaE1);
setEpsRel (1.e-3); // desired accuracy of integral over energy bin
Real limit = 1.e-10 / itsETau; // below a certain threshold throw out the tail
if (compare (integrand (deltaE1), limit) == -1) {
if (compare (integrand (deltaE2), limit) == -1) {
return 0.;
}
}
Real answer = qag (deltaE2, deltaE1, 4);
int status = getStatus ();
if (status) {
cout << deltaE1 << " " << deltaE2 << " " << answer << "\n";
cout << integrand (deltaE1) << " " << integrand (deltaE2) << "\n";
}
return qags (deltaE2, deltaE1);
}