Use betafn instead of gammafn on studentt pdf
Use betafn instead of gammafn on studentt pdf

PR-URL: https://github.com/jstat/jstat/pull/139
Reviewed-by: Trevor Norris <9cb5491eb5770dd8e0bf77a8a0335abf5f0488c5@gmail.com>

jstat/jstat,NorthDecoder/jstat,ggonzale/jstat,akrawitz/jstat,JeebsM/jstat,ggonzale/jstat,akrawitz/jstat,JeebsM/jstat,smarden1/jstat,NorthDecoder/jstat,jstat/jstat,smarden1/jstat