Interface SCIP methods missing from PySCIPOpt (#1236)

* Add getNNodesLeft method

* add getNNodesLeft signature to stub

* add getNRuns and refactor statistics tests

* add getNReoptRuns

* add addNNodes

* fix SCIPgetNNodesLeft dtype and reorder methods defintions

Author: adamj34

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ## Unreleased
 ### Added
+- Added methods: `getNNodesLeft()`, `getNRuns()`, `getNReoptRuns()`, `addNNodes()` with tests
 - Added `addConsCumulative()` for SCIP cumulative constraints (#1222)
 - `Expr` and `GenExpr` support `__pos__` magic method like `+Expr` or `+GenExpr`
 - Added type annotations to most methods on the `Model` class

src/pyscipopt/scip.pxd

@@ -1471,6 +1471,9 @@ cdef extern from "scip/scip.h":
     SCIP_Bool SCIPlpExactDiving(SCIP_LPEXACT* lpexact);
 
     # Statistic Methods
+    int SCIPgetNRuns(SCIP* scip)
+    int SCIPgetNReoptRuns(SCIP* scip)
+    void SCIPaddNNodes(SCIP* scip, SCIP_Longint nnodes)
     SCIP_RETCODE SCIPprintStatistics(SCIP* scip, FILE* outfile)
     SCIP_RETCODE SCIPprintStatisticsJson(SCIP* scip, FILE* file)
     SCIP_Longint SCIPgetNNodes(SCIP* scip)
@@ -2134,6 +2137,7 @@ cdef extern from "scip/scip_tree.h":
     SCIP_RETCODE SCIPgetNSiblings(SCIP* scip)
     SCIP_RETCODE SCIPgetLeaves(SCIP* scip, SCIP_NODE*** leaves, int* nleaves)
     SCIP_Longint SCIPgetNLeaves(SCIP* scip)
+    int SCIPgetNNodesLeft(SCIP* scip)
     SCIP_NODE* SCIPgetBestSibling(SCIP* scip)
     SCIP_NODE* SCIPgetBestLeaf(SCIP* scip)
     SCIP_NODE* SCIPgetPrioChild(SCIP* scip)

src/pyscipopt/scip.pxi

@@ -3296,6 +3296,39 @@ cdef class Model:
         """
         return SCIPgetNLPIterations(self._scip)
 
+    def getNRuns(self):
+        """
+        Gets number of branch and bound runs performed, including the current run
+
+        Returns
+        -------
+        int
+
+        """
+        return SCIPgetNRuns(self._scip)
+
+    def getNReoptRuns(self):
+        """
+        Gets number of reoptimization runs performed, including the current run
+
+        Returns
+        -------
+        int
+
+        """
+        return SCIPgetNReoptRuns(self._scip)
+
+    def addNNodes(self, nnodes):
+        """
+        Add given number to the number of processed nodes in current run and in all runs, including the focus node
+
+        Parameters
+        ----------
+        nnodes : int
+
+        """
+        SCIPaddNNodes(self._scip, nnodes)
+
     def getNNodes(self):
         """
         Gets number of processed nodes in current run, including the focus node.
@@ -3351,6 +3384,17 @@ cdef class Model:
         """
         return SCIPgetNLeaves(self._scip)
 
+    def getNNodesLeft(self):
+        """
+        Gets number of nodes left in the tree (children + siblings + leaves)
+
+        Returns
+        -------
+        int
+
+        """
+        return SCIPgetNNodesLeft(self._scip)
+
     def getNChildren(self):
         """
         Gets number of children of focus node.

src/pyscipopt/scip.pyi

@@ -1262,9 +1262,13 @@ class Model:
     def getMemTotal(self) -> int: ...
     def getMemExternEstim(self) -> int: ...
     def getNLeaves(self) -> int: ...
+    def getNNodesLeft(self) -> int: ...
     def getNLimSolsFound(self) -> int: ...
     def getNNlRows(self) -> int: ...
     def getNNodeLPIterations(self) -> int: ...
+    def getNRuns(self) -> int: ...
+    def getNReoptRuns(self) -> int: ...
+    def addNNodes(self, nnodes: int) -> None: ...
     def getNNodes(self) -> int: ...
     def getNReaders(self) -> int: ...
     def getNSepaRounds(self) -> int: ...

tests/test_node.py

@@ -45,6 +45,14 @@ def eventexec(self, event):
         assert children == self.model.getChildren()
         assert siblings == self.model.getSiblings()
 
+        nodes_left = self.model.getNNodesLeft()
+        assert (
+            nodes_left
+            == self.model.getNLeaves()
+            + self.model.getNChildren()
+            + self.model.getNSiblings()
+        )   
+
         return {'result': SCIP_RESULT.SUCCESS}
 
 def test_tree_methods():

tests/test_statistics.py

@@ -1,21 +1,49 @@
 import os
 from helpers.utils import random_mip_1
 from json import load
+import pytest
 
-def test_statistics_json():
-    model = random_mip_1()
+
+@pytest.fixture
+def optimized_model():
+    model = random_mip_1(small=True)  # Using small=True for speed across tests
     model.optimize()
-    model.writeStatisticsJson("statistics.json")
+    return model
+
+
+def test_statistics_json(optimized_model):
+    optimized_model.writeStatisticsJson("statistics.json")
 
     with open("statistics.json", "r") as f:
         data = load(f)
         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()
+
+def test_getPrimalDualIntegral(optimized_model):
+    primal_dual_integral = optimized_model.getPrimalDualIntegral()
 
     assert isinstance(primal_dual_integral, float)
+
+
+def test_getNRuns(optimized_model):
+    n_runs = optimized_model.getNRuns()
+
+    assert isinstance(n_runs, int)
+    assert n_runs >= 1
+
+
+def test_getNReoptRuns(optimized_model):
+    n_reopt_runs = optimized_model.getNReoptRuns()
+
+    assert isinstance(n_reopt_runs, int)
+    assert n_reopt_runs >= 0
+
+
+def test_addNNodes(optimized_model):
+    initial_n_nodes = optimized_model.getNTotalNodes()
+    optimized_model.addNNodes(5)
+    new_n_nodes = optimized_model.getNTotalNodes()
+
+    assert new_n_nodes == initial_n_nodes + 5