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getact

getact


Purpose
Get the activity value of a robust constraint.
Synopsis
function getact(rc:robustctr):real
Argument
rc 
A robust constraint
Return value
Solution value or 0.
Further information
This function returns returns the value of the left-hand side of a constraint with the current realization of the solution and the uncertains. Therefore, if a constraint is of the form u*x + v*y + z ≤ 3 and x,y,zare variables while u,v are uncertains, the current realization of x,y,z,u,v will be used to return u*x + v*y + z. Note that robust equality constraints (for instance, u*x + v*y + z = 3) have a special status in Mosel. The value of uncertains u and v is, in general, related to an inequality constraint and can be safely obtained in this case only. In order to use getact for equality robust constraints as well, it would be best to decompose these constraints into two inequality constraints ( i.e. u*x + v*y + z ≤ 3 and u*x + v*y + z ≥ 3) and then request u and v from each of the two constraints. Note that both uncertains might differ in value when requested from either inequality constraint.
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