[fpc-pascal] Special math. functions (erf, erfc, ...)

[astlab at inwind.it]

Hi Hansi,

> > I'm searching for FreePascal implementations of some special
> > mathematical functions related to statistics like erf, erfc and some
> > other cumulative probability functions. Did anybody implement such
> > functions already (e.g. from the Numerical Recipies)?
>
> Some functions are available here in the unit ustat.zip:
>
> http://www.polarhome.com/~franco
>
> Thanks for the hint! I can now calculate normal distribution and
> chi-distribution. Do you know where I can find documentation on how
> to calculate the ciritcal values (i.e. inverse) of students' (t)
> distribution, F-distribution and for some non-parametric tests
> (Newman-Keuls-test, Cochran-Test, U-Test, ...)

The direct/inverse students' distribution and F-distribution are
in the sources stdtrl.c and fdtrl.c of the Moshier's ldouble C library:

http://www.moshier.net/ldouble.zip

You can read about Cochran and SNK methods in many books, also available
via web. A starting point for statistics resources may be the site

http://home.ubalt.edu/ntsbarsh/Business-stat/R.htm

Franco