Draw parameters from the approximating distributions

def draw_variables(self):
        """
        Draw parameters from the approximating distributions
        """        
        z = self.q[0].draw_variable_local(self.sims)
        for i in range(1,len(self.q)):
            z = np.vstack((z,self.q[i].draw_variable_local(self.sims)))
        return z