Log PDF for Inverse Wishart prior

        Parameters
        ----------
        X : float
            Covariance matrix for which the prior is being formed over

        Returns
        ----------
        - log(p(X))

def logpdf(self, X):
        """
        Log PDF for Inverse Wishart prior

        Parameters
        ----------
        X : float
            Covariance matrix for which the prior is being formed over

        Returns
        ----------
        - log(p(X))
        """
        return invwishart.logpdf(X, df=self.v, scale=self.Psi)