Hello,
I added 2 functions to the "randist" module
(modified files: gsl_randist.h, gauss.c) which compute
1) P(X <=x) <--> double
gsl_ran_ugaussian_cuml_inf (const double x)
2) P(X >=x) <-->
double gsl_ran_ugaussian_cuml_sup (const double x)
--
Fabrice Lebel