Call a specific set element inside a procedure

[Gabriela G.]

I have a set called "Lines" and its respective index is "i"

I have an indexed paremeter called "Length(i)"

I have a scalar parameter called "best" that gives me a number representing whic is the best line.

I have a scalar parameter called "auxiliar"

When I try to change the value of the parameter inside a procedure there is no error:

Length(i | i=ElementCast(Lines, best)):= 0;

But when I try to change the value of another parameter with the expression Length(i | i=ElementCast(Lines, best)) on the other side of the assignment it shows an error.

auxiliar:=Length(i | i=ElementCast(Lines, best));

The error/warning that appears says: "The scope of index "c" has not been specified" 

[Mohan]

Hello Gabriela,

If you double click on the error message, is it taking you to the auxiliar := Length(...) statement ?

The error message is about an index c and you are not using c anywhere in this statement, so I wonder if it is related to some other statement in that procedure. Can you paste the code you have in that procedure here ?

[Gabriela G.]

It was a mistake, The error/warning that appears says: "The scope of index "i" has not been specified"

If I double click on the error message, is takes me to "auxiliar := Length(...) "

[Mohan]

Thanks for the clarification Gabriela.

Can you clarify whether best is a numeric parameter or a string parameter or an element parameter ?

Are you using it to store the line (line-1, line-2 and so on) which has the max lengths(i) ?

Then make it an element parameter with range set Lines and definition argmax(i, Lengths(i)).

For auxiliar, you can use

auxiliar := Lengths(best)

[Gabriela G.]

The elements of Lines are {1, 2, 3, 4, ...}

best is a numeric parameter

When I try to do auxiliar:=Length(best); it shows an error that says "The first index is of type numeric and cannot be casted to the declaration set Lines."

[Mohan]

Hello Gabriela,

You need not and should not use ElementCast here as best is a numeric parameter and is not a set element.

You have two options.

Make the set Lines as a subset of the predeclared set, Integers. Then set the property - elements are Numeric.

Now, best will be argmax(l, lengths(l)).

Set Lines {
    SubsetOf: Integers;
    Index: l;
    Property: ElementsAreNumerical;
    Definition: data{1..4};
}

Parameter best {
    Definition: argmax(l, Lengths(l));
}

Now, you can use

auxiliar := Lengths(best)

Another option will be to store the ordinance of the Line which has the best length. Here, you will not need to set Lines as a subset of Integers.

Parameter best {
    Definition: Ord(argmax(l, Lengths(l)));
}

Now, auxiliar will be

auxiliar := Lengths(Element(Lines, best));

[Gabriela G.]

Thanks!

El miércoles, 8 de mayo de 2019, 14:33:11 (UTC-5), Gabriela G. escribió: