Re: Directed rounding

[Eric Walter]

Dear Juan Pablo,

Thanks for your quick reaction. What I need is a simple way of computing the smallest floatting point number that is larger than some given real number that may be the result of some computation, as well as the largest floatting point number that is smaller that the same real number. This corresponds to two of the four rounding modes demanded by IEEE 747. As far as I know, none of the functions that you mention perform that. MATLAB does not do it, Scilab does not do it either. To see how these rounding modes may be used to assess number of significant digits, you may consult chapter 14 of the book

http://www.springer.com/fr/book/9783319076706#reviews

Best,

Eric

Le 17/09/2015 17:43, Juan Pablo Carbajal a écrit :

On Thu, Sep 17, 2015 at 4:47 PM, Eric Walter
<address@hidden> wrote:

Dear colleagues,

If this is not already the case, would you please consider making directed
rounding, as made available on all IEEE 747 compliant processors, simply
accessible to gnu-octave users? This would help assessing the number of
significant digits in the results of floatting-point computation.

Best regards,

Eric Walter

Dear Eric,

I might not get the point correctly, but are the functions round, fix,
floor, ceil, sign, chop not doing what you need?