Add test for _createConsBasicLinear and README

Author: Joao-Dionisio

CHANGELOG.md

@@ -2,6 +2,8 @@
 
 ## Unreleased
 ### Added
+- Added transformProb but no test
+- Added _createConsBasicLinear and test
 - Expanded Statistics class to more problems.
 - Created Statistics class
 - Added parser to read .stats file

src/pyscipopt/scip.pxi

@@ -4140,14 +4140,16 @@ cdef class Model:
         free(coeffs_array)
         return PyCons
 
-    def _createConsBasicLinear(self, ExprCons lincons, **kwargs):
+    def _createConsBasicLinear(self, ExprCons lincons, name='', **kwargs):
         """
         The function for creating a basic linear constraint, but not adding it to the Model.
 
         Parameters
         ----------
         lincons : ExprCons
-        kwargs : dict, optional
+        name    : str, optional
+            name of constraint
+        kwargs  : dict, optional
 
         Returns
         -------
@@ -4161,6 +4163,13 @@ cdef class Model:
 
         cdef SCIP_CONS* scip_cons
 
+        if name == '':
+            name = 'c'+str(SCIPgetNConss(self._scip)+1)
+
+        kwargs = dict(name=name)
+        kwargs['lhs'] = -SCIPinfinity(self._scip) if lincons._lhs is None else lincons._lhs
+        kwargs['rhs'] =  SCIPinfinity(self._scip) if lincons._rhs is None else lincons._rhs
+
         cdef int nvars = len(terms.items())
 
         vars_array = <SCIP_VAR**> malloc(nvars * sizeof(SCIP_VAR*))
@@ -4178,6 +4187,8 @@ cdef class Model:
 
         free(vars_array)
         free(coeffs_array)
+        
+        PY_SCIP_CALL(SCIPreleaseCons(self._scip, &scip_cons))
         return PyCons
 
     def _createConsQuadratic(self, ExprCons quadcons, **kwargs):
@@ -9047,7 +9058,7 @@ cdef class Model:
                                  SCIP_STAGE_SOLVING,
                                  SCIP_STAGE_SOLVED]:
             raise Warning("method cannot be called in stage %i." % self.getStage)
-            
+
         PY_SCIP_CALL(SCIPfreeReoptSolve(self._scip))
 
     def chgReoptObjective(self, coeffs, sense = 'minimize'):

tests/test_cons.py

@@ -204,6 +204,18 @@ def test_addConsDisjunction_expr_init():
     assert m.isEQ(m.getVal(y), 5)
     assert m.isEQ(m.getVal(o), 6)
 
+def test__createConsBasicLinear():
+    m = Model()
+    x = m.addVar()
+    y = m.addVar()
+
+    assert m.getNConss() == 0
+
+    c = m._createConsBasicLinear(x+y<=4)
+
+
+    assert m.getNConss() == 0
+    assert c.isLinear()
 
 @pytest.mark.skip(reason="TODO: test getValsLinear()")
 def test_getValsLinear():

tests/test_model.py

@@ -476,4 +476,4 @@ def test_getObjVal():
     assert m.getVal(x) == 0
 
     assert m.getObjVal() == 16 
-    assert m.getVal(x) == 0
+    assert m.getVal(x) == 0