for .
If
is continuous and strictly
increasing, then
is the unique value
satisfying .
The generalized-inverse definition remains valid for discrete
distributions and other cases in which has jumps or constant intervals.
Hyndman, R. J. and Fan, Y. "Sample Quantiles in Statistical Packages." Amer. Stat.50, 361-365, 1996.Shaw,
W. "Refinement of the Normal Quantile: A Benchmark Normal Quantile Based on
Recursion, and an Appraisal of the Beasley-Springer-Moro, Acklam, and Wichura (AS241)
Methods." 2007. http://www.mth.kcl.ac.uk/~shaww/web_page/papers/NormalQuantile1.pdf.