@article{JSSv023c01, title={Accurate Computation of the F-to-z and t-to-z Transforms for Large Arguments }, volume={23}, url={https://www.jstatsoft.org/index.php/jss/article/view/v023c01}, doi={10.18637/jss.v023.c01}, abstract={The obvious method for transforming an F or t variate into a z variate is via the corresponding p value, but this method is inaccurate when F or t is so large that p differs from 1 by only the last few bits of its floating-point representation. More accurate results may be obtained by using q = 1 - p as the intermediate variable so that the full precision of the floating-point representation is available. }, number={1}, journal={Journal of Statistical Software, Code Snippets}, author={Hughett, Paul}, year={2007}, pages={1–5} }