id,summary,reporter,owner,description,type,status,milestone,component,version,severity,resolution,keywords,cc
7259,Boost.Math non-central t distribution does not permit infinite degrees of freedom,Paul A. Bristow,Paul A. Bristow,"st.Math non-central t distribution does not permit infinite degrees of freedom (unlike the Central Student's t).

Requested by Thomas Mang.

This has now been added, and in the process some improvement in the accuracy and speed at higher degrees of freedom (nu)and big non-centrality (delta) (by using the faster and more accurate Student's t distribution or Normal distribution where appropriate).

After discussion with Thomas Mang and John Maddock, by examination of a Cornish Fisher expansion, the cross-over point has been selected as 

 if( delta / (4 * nu)) < epsilon<FPT>)

use Students t. 





 ",Feature Requests,closed,To Be Determined,math,Boost 1.52.0,Optimization,fixed,math non-central students t distribution,