def propose_unif(self):
        """Propose a new live point by sampling *uniformly*
        within the ellipsoid."""

        while True:
            # Sample a point from the ellipsoid.
            u = self.ell.sample(rstate=self.rstate)

            # Check if `u` is within the unit cube.
            if unitcheck(u, self.nonperiodic):
                break  # if it is, we're done!

        return u, self.ell.axes
Propose a new live point by sampling *uniformly*
        within the ellipsoid.