[PPL-devel] Another question

[Ezio Bartocci]

Can i use the mpz_class instead of mpf_class for an arbitrary integer
precision ?

On Fri, May 4, 2012 at 5:25 PM, Ezio Bartocci <ezio.bartocci at gmail.com> wrote:
> so for integral you mean integers ? So it mean that accept only
> rational number in the set of Q ?
>
> On Thu, May 3, 2012 at 11:10 PM, Enea Zaffanella <zaffanella at cs.unipr.it> wrote:
>> On 05/03/2012 06:13 PM, Ezio Bartocci wrote:
>>>
>>> Dear PPL developers,
>>>
>>>        I forward the message that I sent to Roberto. Since he is
>>> traveling, maybe some of you can help us...
>>>
>>> Thanks a lot
>>>
>>> Best Regards
>>>
>>> Ezio
>>
>>
>>
>> Hello Ezio.
>>
>> I suspect the main problem is in the right hand side of the line:
>>
>>
>>>>                 lin_exp[j]+=single_point[m]*(*it);
>>
>> Here single_point[m] has type mpf_class.
>> However, the PPL only supports *integral* coefficients.
>>
>> When a generator has non-integral coordinates, it can be expressed using
>> integral coefficients and providing a common divisor.
>>
>> For instance, if you need to specify a point in 3d having coordinates
>>  (1.5, 0.5, 2.5)
>> you can express it as
>>  (3, 1, 5) / 2
>>
>> In C++, something like the following:
>>
>>  Variable A(0);
>>  Variable B(1);
>>  Variable C(2);
>>  Linear_Expression le = 3*A + B + 5*C;
>>  ph.add_generator(point(le, 2));
>>
>> where the second argument to `point' is the divisor
>> (that gets applied to all the coefficients of `le').
>>
>> Hope this helps.
>>
>> Regards,
>> Enea.
>
>
>
> --
> Dr. Ezio Bartocci, Assistant Professor
> Dependable Systems Group
> Department of Computer Engineering
> Faculty of informatics
> TU Wien, Vienna University of Technology, Austria
> Treitlstraße   3, 1040 Vienna, Austria
> E-Mail:     ezio.bartocci at tuwien.ac.at
> Phone:     +43 (1) 58801 - 18210
> Webiste: http://www.eziobartocci.com



-- 
Dr. Ezio Bartocci, Assistant Professor
Dependable Systems Group
Department of Computer Engineering
Faculty of informatics
TU Wien, Vienna University of Technology, Austria
Treitlstraße   3, 1040 Vienna, Austria
E-Mail:     ezio.bartocci at tuwien.ac.at
Phone:     +43 (1) 58801 - 18210
Webiste: http://www.eziobartocci.com