WP 34S and 31S bugs and fixes

[Paul Dale]

Not a bug, but an improvement nonetheless.

I finally replaced three of the quantile functions with Dieter's improved versions last night. This should have an impact on speed and accuracy for both the 31S and 34S. This will be most marked for the χ² quantile function -- previously it used a generic Newton based solver, now it is using a custom solver with cubic convergence. The other two quantile functions modified are Student's T and the normals.

I've still got an accuracy improvement for the Student's T CDF to put in, hopefully this weekend.


That just leaves Snedecor's F, Poisson and Binomial using the generic solver.


- Pauli