Add getPrimalDualIntegral() from C API

CHANGELOG.md

@@ -8,6 +8,7 @@
 - Added pre-commit hook for automatic stub regeneration (see .pre-commit-config.yaml)
 - Wrapped isObjIntegral() and test
 - Added structured_optimization_trace recipe for structured optimization progress tracking
+- Added methods: getPrimalDualIntegral()
 ### Fixed
 - getBestSol() now returns None for infeasible problems instead of a Solution with NULL pointer
 - all fundamental callbacks now raise an error if not implemented

src/pyscipopt/scip.pxd

@@ -1473,6 +1473,7 @@ cdef extern from "scip/scip.h":
     int SCIPgetPlungeDepth(SCIP* scip)
     SCIP_Longint SCIPgetNNodeLPIterations(SCIP* scip)
     SCIP_Longint SCIPgetNStrongbranchLPIterations(SCIP* scip)
+    SCIP_Real SCIPgetPrimalDualIntegral(SCIP* scip)
 
     # Parameter Functions
     SCIP_RETCODE SCIPsetBoolParam(SCIP* scip, char* name, SCIP_Bool value)

src/pyscipopt/scip.pxi

@@ -316,7 +316,7 @@
     if rc == SCIP_OKAY:
         pass
     elif rc == SCIP_ERROR:
         raise Exception('SCIP: unspecified error!')
     elif rc == SCIP_NOMEMORY:
         raise MemoryError('SCIP: insufficient memory error!')
     elif rc == SCIP_READERROR:
@@ -335,7 +335,7 @@
         raise Exception('SCIP: method cannot be called at this time'
                             + ' in solution process!')
     elif rc == SCIP_INVALIDDATA:
         raise Exception('SCIP: error in input data!')
     elif rc == SCIP_INVALIDRESULT:
         raise Exception('SCIP: method returned an invalid result code!')
     elif rc == SCIP_PLUGINNOTFOUND:
@@ -3385,6 +3385,16 @@
         """
         return SCIPgetNStrongbranchLPIterations(self._scip)
 
+    def getPrimalDualIntegral(self):
+        """
+        Recomputes and returns the primal dual gap stored in the stats
+
+        Returns
+        ------
+        float
+        """
+        return SCIPgetPrimalDualIntegral(self._scip)
+
     def cutoffNode(self, Node node):
         """
         marks node and whole subtree to be cut off from the branch and bound tree.

src/pyscipopt/scip.pyi

@@ -1129,6 +1129,7 @@ class Model:
     def getNSols(self) -> Incomplete: ...
     def getNSolsFound(self) -> Incomplete: ...
     def getNStrongbranchLPIterations(self) -> Incomplete: ...
+    def getPrimalDualIntegral(self) -> Incomplete: ...
     def getNTotalNodes(self) -> Incomplete: ...
     def getNVars(self, transformed: Incomplete = ...) -> Incomplete: ...
     def getNVarsAnd(self, and_cons: Incomplete) -> Incomplete: ...

tests/test_statistics.py

@@ -12,3 +12,10 @@ def test_statistics_json():
         assert data["origprob"]["problem_name"] == "model"
 
     os.remove("statistics.json")
+
+def test_getPrimalDualIntegral():
+    model = random_mip_1(small=True)
+    model.optimize()
+    primal_dual_integral = model.getPrimalDualIntegral()
+
+    assert isinstance(primal_dual_integral, float)