Get activity value for a constraint.

Activity value for the constraint, 0 in case of an error.

XPRBprob expl2;
XPRBctr ctr2;
XPRBarrvar ty1;
double act
   ...
expl2 = XPRBnewprob("example2");
ty1 = XPRBnewarrvar(expl2, 5, XPRB_PL, "arry1", 0, 500);
ctr2 = XPRBnewsum(expl2, "r2", ty1, XPRB_E, 9);
XPRBlpoptimize(expl2, "");
act = XPRBgetact(ctr2);

This obtains the activity value for the constraint ctr2.

This function returns the activity value for a constraint. It may be used with constraints that are not part of the problem (in particular, constraints without relational operators, that is, constraints of type XPRB_N). In this case the function returns the evaluation of the constraint terms involving variables that are in the problem. Otherwise, the constraint activity is calculated as activity = RHS – slack.
If this function is called after completion of a global search and an integer solution has been found (that is, if function XPRBgetmipstat returns values XPRB_MIP_SOLUTION or XPRB_MIP_OPTIMAL), it returns the value corresponding to the best integer solution. If no solution is available this function outputs a warning and returns 0. In all other cases it returns the activity value in the last LP that has been solved. If this function is used during the execution of an optimization process (for instance in Optimizer library callback functions) it needs to be preceded by a call to XPRBsync with the flag XPRB_XPRS_SOL.

XPRBgetdual, XPRBgetobjval, XPRBgetrcost, XPRBgetslack, XPRBgetsol, XPRBsync.