“…As mentioned in Frumento and Bottai (2016); Yang et al (2017);Frumento et al (2021), valid choices of b (τ ) are, for example, functions of the form τ α , log(τ ), log(1 − τ ), α τ , the quantile function of any distribution with finite moments, splines, or a combination of the above. In general, the selected basis set b (τ ) should satisfy two conditions.…”