fixes #348: options in SCIP_CMD. Added timeLimit and maxNodes argumen…

…ts to SCIP_CMD to interface.

pulp/apis/scip_api.py

@@ -35,15 +35,18 @@ class SCIP_CMD(LpSolver_CMD):
     """The SCIP optimization solver"""
     name ='SCIP_CMD'
 
-    def __init__(self, path=None, keepFiles=False, mip=True, msg=True, options=None):
+    def __init__(self, path=None, keepFiles=False, mip=True, msg=True, options=None, timeLimit=None, maxNodes=None):
         """
         :param bool mip: if False, assume LP even if integer variables
         :param bool msg: if False, no log is shown
         :param list options: list of additional options to pass to solver
         :param bool keepFiles: if True, files are saved in the current directory and not deleted after solving
         :param str path: path to the solver binary
+        :param float timeLimit: maximum time for solver (in seconds)
+        :param int maxNodes: max number of nodes during branching. Stops the solving when reached.
         """
-        LpSolver_CMD.__init__(self, mip=mip, msg=msg, options=options, path=path, keepFiles=keepFiles)
+        LpSolver_CMD.__init__(self, mip=mip, msg=msg, options=options, path=path,
+                              keepFiles=keepFiles, timeLimit=timeLimit, maxNodes=maxNodes)
 
     SCIP_STATUSES = {
         'unknown': constants.LpStatusUndefined,
@@ -82,13 +85,18 @@ def actualSolve(self, lp):
 
         tmpLp, tmpSol = self.create_tmp_files(lp.name, 'lp', 'sol')
         lp.writeLP(tmpLp)
-        proc = [
-            '%s' % self.path, '-c', 'read "%s"' % tmpLp, '-c', 'optimize',
-            '-c', 'write solution "%s"' % tmpSol, '-c', 'quit'
-        ]
+
+        proc = ['%s' % self.path, '-c', 'read "%s"' % tmpLp]
+        if self.timeLimit is not None:
+            proc.extend(['-c', 'set limits time {}'.format(self.timeLimit)])
+
+        maxNodes = self.optionsDict.get('maxNodes')
+        if maxNodes is not None:
+            proc.extend(['-c', 'set limits nodes {}'.format(maxNodes)])
         proc.extend(self.options)
         if not self.msg:
             proc.append('-q')
+        proc.extend(['-c', 'optimize', '-c', 'write solution "%s"' % tmpSol, '-c', 'quit'])
 
         self.solution_time = clock()
         subprocess.check_call(proc, stdout=sys.stdout, stderr=sys.stderr)