Re: [AIMMS] equality constraint tolerance doesn't work

[Luis Pinto]

Hello Erica,

I looked up the option in the help (F1)

Here is the description:

Execution Tolerances - Equality Relative Tolerance

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Type: Floating point number Range: [0.0, 0.9] Default: 1e-13 For two real numbers x and y the result of the comparison x < y (or any of the other relational operators =, <>, >, >=, or <=) depends on two tolerances: • Equality Absolute Tolerance, and • Equality Relative Tolerance. For a detailed description of these two tolerances and numerical comparison in AIMMS, you should read the corresponding section in the Language Reference. Note • This option has no influence on the feasibility of constraints. • This option influences assignments in the following way; when a value is assigned to an identifier that is equal to the default of that identifier, equal within the above tolerances, the assignment will be ignored.

So this options does not affect tolerances within a mathematical model.
If you are looking to define the tolerance in a math model, you should set the option in the section of that solver. Do a search in the project with tolerance.

Hope it helps,
Cheers,

Luis Pinto
www.unisoma.com.br

On 6 April 2012 18:37, erica ye <erica...@gmail.com> wrote:

I have equality constraints in my problem.
I've set  'Equality relative tolerance' to 1e-6 (P.88 in AIMMS_ref),
and get following error:
"The empty row EqualityConstrity(1,A) .. 0=9.99998519546e-008 is
infeasible.".

I use f(x) <=0.0001 and f(x)>=-0.0001 to replace the equality
constraint, and that error doesn't show anymore.
I don't know why cannot the equality relative tolerance work.

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[erica ye]

Thanks you so much!
I use the bound tolerance and it works!

On 4月6日, 上午11时47分, Luis Pinto <luisf...@gmail.com> wrote:
> Hello Erica,
>
> I looked up the option in the help (F1)
>
> Here is the description:
>
> Execution Tolerances - Equality Relative Tolerance

> Top <aimms.htm> Previous <execution_tolerances___equalit.htm>
> Next<execution_tolerances___gui_non.htm>

>
> Type: Floating point number
> Range: [0.0, 0.9]
> Default: 1e-13
>
> For two real numbers x and y the result of the comparison x < y (or any of
> the other relational operators =, <>, >, >=, or <=) depends on two
> tolerances:

> * Equality Absolute Tolerance, and
> * Equality Relative Tolerance.

>
> For a detailed description of these two tolerances and numerical comparison
> in AIMMS, you should read the corresponding section in the Language
> Reference.
>
> Note

> * This option has no influence on the feasibility of constraints.
> * This option influences assignments in the following way; when a value

> is assigned to an identifier that is equal to the default of that
> identifier, equal within the above tolerances, the assignment will be
> ignored.
>
> So this options does not affect tolerances within a mathematical model.
> If you are looking to define the tolerance in a math model, you should set
> the option in the section of that solver. Do a search in the project with
> tolerance.
>
> Hope it helps,
> Cheers,
>
> Luis Pintowww.unisoma.com.br
>