- QuantLib
- OneFactorGaussianStudentCopula
 
One-factor Gaussian-Student t-Copula. More...
#include <ql/experimental/credit/onefactorstudentcopula.hpp>

| Public Member Functions | |
| OneFactorGaussianStudentCopula (const Handle< Quote > &correlation, int nz, Real maximum=10, Size integrationSteps=200) | |
| Real | density (Real m) const | 
| Density function of M. | |
| Real | cumulativeZ (Real z) const | 
| Cumulative distribution of Z. | |
One-factor Gaussian-Student t-Copula.
The copula model
![\[ Y_i = a_i\,M+\sqrt{1-a_i^2}\:Z_i \]](form_88.png) 
is specified here by setting the probability density functions for  (
 (  ) to a Student t-distributions with
) to a Student t-distributions with  degrees of freedom, and for
 degrees of freedom, and for  (
 (  ) to a Gaussian.
) to a Gaussian.
The variance of the Student t-distribution with  degrees of freedom is
 degrees of freedom is  . Since the copula approach requires zero mean and unit variance distributions,
. Since the copula approach requires zero mean and unit variance distributions,  is scaled by
 is scaled by 
Density function of M.
Derived classes must override this method and ensure zero mean and unit variance.
Implements OneFactorCopula.
| Real cumulativeZ | ( | Real | z | ) | const  [virtual] | 
Cumulative distribution of Z.
Derived classes must override this method and ensure zero mean and unit variance.
Implements OneFactorCopula.