def cosi_pdf(z,k=1):
    """Equation (11) of Morton & Winn (2014)
    """
    return 2*k/(np.pi*np.sinh(k)) * quad(cosi_integrand,z,1,args=(k,z))[0]
def cosi_pdf ( z , k = 1 ) : return 2 * k / ( np . pi * np . sinh ( k ) ) * quad ( cosi_integrand , z , 1 , args = ( k , z ) ) [ 0 ]
Equation (11) of Morton & Winn (2014)