[Rd] Problem with R math library.

[Guillaume Yziquel]

Dirk Eddelbuettel a écrit :
>
> Salut Guilluame,
>
> | > val norm_rand : unit -> float
> | > Random variates from the standard normal distribution. Bug: currently systematically returns -8.77332116900134373.
> | 
> | Any idea as to why the function systematically returns the same value? 
> | Is there a way the math library should be initialised?
> 
> I think it is pretty clearly documented in R-exts:
> 
>   However, before these are used, the user must call
>   
>        GetRNGstate();
>   
>   and after all the required variates have been generated, call
>   
>        PutRNGstate();
>   
>   These essentially read in (or create) `.Random.seed' and write it out
>   after use.

Fair enough. I admit I've been busy with low detail stuff, and omitted 
to come back to R-exts.

However, I have another question on which I do not find information (I 
found it once, but do not know how to find it again...): What's the big 
difference between using the R mathematical library in standalone mode 
and not in standalone mode? How does it translate in terms of C 
directives and linking modalities? I've noticed the MATHLIB_STANDALONE 
macro, but I do not know how I should use it...

All the best,

-- 
      Guillaume Yziquel
http://yziquel.homelinux.org/