[Scip] epsilon for functions isPositive, isZero, etc

[Gregor Hendel]

Hi Alessia,

the parameter is located under  "numerics/epsilon". For the satisfaction 
of constraints,
there is "numerics/feastol", which is less strict with a default value 
of 1e-6.

Best,
Gregor

Am 27.01.2014 12:05, schrieb Alessia Violin:
> Hello Matthias,
>
> thanks! Is there a function to change the epsilon once for all those 
> functions? it would be quicker to test different values!
>
> Alessia
>
>
> On 01/27/2014 11:59 AM, Matthias Miltenberger wrote:
>> Hi Alessia,
>>
>> SCIP uses 1e-9 as default epsilon for these functions. It can be changed
>> to a value in the range of 1e-20 to 1e-3.
>>
>> best
>> Matthias
>>
>> On 27.01.2014 11:17, Alessia Violin wrote:
>>> Hello!
>>>
>>> I was wondering which is the "epsilon" used in the functions
>>> SCIPisPosite, isZero, isEQ, etc? I tried to find this information in 
>>> the
>>> developer's manual but I didn't succeed.
>>>
>>> I have a branch-and-cut-and-price code with quite a lot of other things
>>> (stabilisation, heuristics, ...), and if the epsilon is too small the
>>> convergence of column generation is very slow, and if it's too big 
>>> there
>>> are some particular configurations of parameters for which optimal
>>> columns are not generated. Moreover this also depends on the magnitude
>>> of the data for different set of instances and I am trying to figure 
>>> out
>>> the best epsilon to use.
>>>
>>> Thanks in advance!
>>>
>>> Alessia
>>>
>>>
>