Merge remote-tracking branch 'origin/v9-minor'

CHANGELOG

@@ -91,6 +91,8 @@ Interface changes
 
 ### New API functions
 
+- New function SCIPgetExprActivityNonlinear() to get activity of nonlinear constraint.
+
 ### Command line interface
 
 ### Interfaces to external software

src/scip/cons_nonlinear.c

@@ -13777,6 +13777,32 @@ SCIP_RETCODE SCIPaddExprNonlinear(
    return SCIP_OKAY;
 }
 
+/** computes value of constraint expression in a given solution
+ *
+ * Stores value of constraint expression in sol in activity.
+ * In case of a domain error (function cannot be evaluated in sol), activity is set to SCIP_INVALID.
+ */
+SCIP_RETCODE SCIPgetExprActivityNonlinear(
+   SCIP*                 scip,               /**< SCIP data structure */
+   SCIP_CONS*            cons,               /**< constraint */
+   SCIP_SOL*             sol,                /**< solution */
+   SCIP_Real*            activity            /**< buffer to store computed activity */
+   )
+{
+   SCIP_CONSDATA* consdata;
+
+   assert(cons != NULL);
+   assert(activity != NULL);
+
+   consdata = SCIPconsGetData(cons);
+   assert(consdata != NULL);
+
+   SCIP_CALL( SCIPevalExpr(scip, consdata->expr, sol, 0L) );
+   *activity = SCIPexprGetEvalValue(consdata->expr);
+
+   return SCIP_OKAY;
+}
+
 /** gets absolute violation of nonlinear constraint
  *
  * This function evaluates the constraints in the given solution.

src/scip/cons_nonlinear.h

@@ -807,6 +807,19 @@ SCIP_RETCODE SCIPregisterExprUsageNonlinear(
    SCIP_Bool             useactivityforsepaabove  /**< whether activity of expr will be used by overestimation */
    );
 
+/** computes value of constraint expression in a given solution
+ *
+ * Stores value of constraint expression in sol in activity.
+ * In case of a domain error (function cannot be evaluated in sol), activity is set to SCIP_INVALID.
+ */
+SCIP_EXPORT
+SCIP_RETCODE SCIPgetExprActivityNonlinear(
+   SCIP*                 scip,               /**< SCIP data structure */
+   SCIP_CONS*            cons,               /**< constraint */
+   SCIP_SOL*             sol,                /**< solution */
+   SCIP_Real*            activity            /**< buffer to store computed activity */
+   );
+
 /** computes absolute violation for auxvar relation in an expression w.r.t. original variables
  *
  * Assume the expression is f(x), where x are original (i.e., not auxiliary) variables.