/// Assigns new values to the parameters.
/// This method assumes that the parameters have been already checked.
private void DefineParameters(double shape1, double shape2)
{
_alpha1 = shape1;
_alpha2 = shape2;
_norm = GammaFunction.LogBeta(_alpha1, _alpha2);
_gamma1 = null;
_gamma2 = null;
_incompleteBetaFunction = null;
}
/// Assigns new degrees of freedom to the receiver.
/// Compute the norm of the distribution after a change of parameters.
/// @param n1 int first degree of freedom
/// @param n2 int second degree of freedom
public void DefineParameters(int n1, int n2)
{
_dof1 = n1;
_dof2 = n2;
double nn1 = 0.5 * n1;
double nn2 = 0.5 * n2;
_norm = nn1 * Math.Log(n1) + nn2 * Math.Log(n2)
- GammaFunction.LogBeta(nn1, nn2);
_incompleteBetaFunction = null;
_chiSquareDistribution1 = null;
_chiSquareDistribution2 = null;
}
/// @param n int degree of freedom
public void DefineParameters(int n)
{
_dof = n;
_norm = -(Math.Log(_dof) * 0.5
+ GammaFunction.LogBeta(_dof * 0.5, 0.5));
}