quant: Estimates the quantiles at a vector of probability values
Description
This method utilizes the estimator (13) in paper Stephanou, Michael,
Varughese, Melvin and Iain Macdonald. "Sequential quantiles via Hermite
series density estimation." Electronic Journal of Statistics 11.1 (2017):
570-607 <doi:10.1214/17-EJS1245>, with some modifications to improve the
stability of numerical root finding when using the bisection algorithm.
Note that this method is only applicable to the univariate Hermite
estimator i.e. est_type = "univariate".