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getsol

getsol


Purpose
Get the realisation of an uncertain or robust constraint.
Synopsis
function getsol(u:uncertain, rc:robustctr):real
function getsol(u:uncertain):real
function getsol(rc:robustctr):real
Arguments
rc 
A robust constraint
An uncertain
Return value
Solution value or 0.
Further information
This function returns the realization of uncertain u for the robust optimization problem solved. The value of u is only available after solving the robust optimization problem. The value of u is 0 if the problem has not been solved or the uncertain or constraint is not contained in the problem that has been solved. If the uncertain u appears in more than one constraint, it is necessary to specify the constraint with function call getsol(u,rc): this is a consequence of robust optimization, for which the same uncertain can assume different values in different constraints. If the uncertain u only appears in one constraint, then it suffices to call getsol(u). The function getsol(rc) returns the evaluation 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 - 3. 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 getsol 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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