Пример #1
0
class TestMinimaSearch(unittest.TestCase):
    def setUp(self):
        self.natoms = 6
        self.system = LJClusterSENS(self.natoms, 2.5)
        
        # create a database
        self.database = self.system.create_database()
        
        # add some minima to the database
        bh = self.system.get_basinhopping(self.database, outstream=None)
        while self.database.number_of_minima() < 2:
            bh.run(1)
        
        self.ndof = self.natoms * 3 - 6
    
        self.minima_searcher = _MinimaSearcher(self.database.minima(), energy_accuracy=1e-4, compare_structures=self.system.get_compare_exact())

    def test_exact(self):
        for m in self.database.minima():
            mret, tform = self.minima_searcher.get_minima(m.energy, m.coords)
            self.assertEqual(m, mret)

    def test_random(self):
        for m in self.database.minima():
            mret, tform = self.minima_searcher.get_minima(m.energy + np.random.uniform(-1e-4, 1e-4), m.coords)
            self.assertEqual(m, mret)
    def test_none(self):
        for m in self.database.minima():
            mret, tform = self.minima_searcher.get_minima(m.energy + 10., m.coords)
            self.assertIsNone(mret)
Пример #2
0
class TestSENSExact_LJ(_test_ns_lj.TestNS_LJ):
    def setUp(self):
        #        self.seed = 4
        #        np.random.seed(self.seed)
        self.setUp1()

    def set_up_system(self):
        self.natoms = 6
        self.gmin = -12.7121
        self.system = LJClusterSENS(self.natoms, 2.5)
        self.ndof = 3 * self.natoms - 6

    def setUp1(self, nproc=1):
        self.set_up_system()
        self.nreplicas = 10
        self.stepsize = 0.01
        self.nproc = nproc

        self.database = self.system.create_database()
        # add some minima to the database
        bh = self.system.get_basinhopping(self.database, outstream=None)
        while self.database.number_of_minima() < 2:
            bh.run(1)
        # compute the thermodynamic information
        get_thermodynamic_information(self.system, self.database)
        get_all_normalmodes(self.system, self.database)

        self.minima = list(self.database.minima())
        assert self.database.number_of_minima(
        ) > 1, "%d minima" % self.database.number_of_minima()

        self.mc_runner = self.system.get_mc_walker(mciter=200)

        self.energy_accuracy = 1e-4
        self.ns = NestedSamplingSAExact(
            self.system,
            self.nreplicas,
            self.mc_runner,
            self.minima,
            self.energy_accuracy,
            mindist=self.system.get_mindist(),
            config_tests=self.system.get_config_tests(),
            stepsize=0.1,
            nproc=nproc,
            verbose=True,
            iprint=100)

        self.Emax0 = self.ns.replicas[-1].energy

        self.run_ns(max_iter=1000, Etol=.001)

    def test1(self):
        super(TestSENSExact_LJ, self).test1()
        self.assertGreater(self.ns.count_sampled_minima, 0)
Пример #3
0
class TestSENSExact_LJ(_test_ns_lj.TestNS_LJ):
    def setUp(self):
#        self.seed = 4
#        np.random.seed(self.seed)
        self.setUp1()
    
    def set_up_system(self):
        self.natoms = 6
        self.gmin = -12.7121
        self.system = LJClusterSENS(self.natoms, 2.5)
        self.ndof = 3*self.natoms - 6


    def setUp1(self, nproc=1):
        self.set_up_system()
        self.nreplicas = 10
        self.stepsize = 0.01
        self.nproc = nproc
        
        self.database = self.system.create_database()
        # add some minima to the database
        bh = self.system.get_basinhopping(self.database, outstream=None)
        while self.database.number_of_minima() < 2:
            bh.run(1)
        # compute the thermodynamic information
        get_thermodynamic_information(self.system, self.database)
        get_all_normalmodes(self.system, self.database)
        

        self.minima = list(self.database.minima())
        assert self.database.number_of_minima() > 1, "%d minima" %  self.database.number_of_minima()
        
        self.mc_runner = self.system.get_mc_walker(mciter=200)

        self.energy_accuracy = 1e-4
        self.ns = NestedSamplingSAExact(self.system, self.nreplicas, self.mc_runner,
                                   self.minima, self.energy_accuracy, 
                                   mindist=self.system.get_mindist(),
                                   config_tests = self.system.get_config_tests(),
                                   stepsize=0.1, nproc=nproc, verbose=True, iprint=100)
        
        self.Emax0 = self.ns.replicas[-1].energy
        
        self.run_ns(max_iter=1000, Etol=.001)
    

    
    def test1(self):
        super(TestSENSExact_LJ, self).test1()
        self.assertGreater(self.ns.count_sampled_minima, 0)
    def setUp1(self, nproc=1):
        self.natoms = 31
        self.system = LJClusterSENS(self.natoms, 2.5)
        self.ndof = 3*self.natoms - 6

        self.nreplicas = 10
        self.stepsize = 0.01
        self.nproc = nproc
        
        
        try:
            self.database = self.system.create_database("/scratch/scratch2/js850/sens/testruns/lj31/lj31.sqlite", createdb=False)
        except IOError:
            self.database = build_database(self.system, 4)
            
        

        self.minima = list(self.database.minima())
        assert self.database.number_of_minima() > 1, "%d minima" %  self.database.number_of_minima()
        
        self.sampler = HSASamplerCluster(self.minima, self.ndof, copy_minima=True, 
                                         center_minima=True, 
                                         compare_structures=self.system.get_compare_exact(), 
                                         mindist=self.system.get_mindist(),
                                         minimizer=self.system.get_minimizer())

        self.Emax = min((m.energy for m in self.minima)) + 1.

        # for performing transformations like rotations, translations, permutations, etc
        self.transform = TransformAtomicCluster()
        
        # this is a list of random transformations that don't change the energy
        self.transformations = [self.rtrans, self.rrot, self.invert, self.rperm]
Пример #5
0
class TestNS_LJ(unittest.TestCase):
    def setUp(self):
        self.setUp1()

    def compute_cv(self, Tmin=.01, Tmax=3., nT=100):
        T = np.arange(Tmin, Tmax, (Tmax - Tmin) / nT)
        Cv = compute_cv_c(np.array(self.ns.max_energies), 
                          float(self.nproc), float(self.ndof), T.min(), T.max(), T.size, float(self.ndof), live=False)
        return T, Cv


    def set_up_system(self):
        self.natoms = 13
        self.gmin = -44.3269
        self.system = LJClusterSENS(self.natoms, 2.5)
        self.ndof = 3 * self.natoms - 6

    def setUp1(self, nproc=1):
        self.set_up_system()
        self.nreplicas = 10
        self.stepsize = 0.01
        self.nproc = nproc
        
        self.mc_runner = self.system.get_mc_walker(mciter=100)

        self.ns = NestedSampling(self.system, self.nreplicas, self.mc_runner, 
                                 stepsize=0.1, nproc=nproc, verbose=False)
        
        self.Emax0 = self.ns.replicas[-1].energy
        
        self.niter = 100
        for i in xrange(self.niter):
            self.ns.one_iteration()
        self.Emax = self.ns.replicas[-1].energy
        self.Emin = self.ns.replicas[0].energy
    
    def test1(self):
        self.assert_(len(self.ns.replicas) == self.nreplicas)
        self.assert_(self.Emax < self.Emax0)
        self.assert_(self.Emin < self.Emax)
        self.assert_(self.Emin < 0)
        self.assert_(self.Emin >= self.gmin)
        self.assert_(self.ns.stepsize != self.stepsize)
        self.assertEqual(len(self.ns.max_energies), self.niter * self.nproc)
        self.assertEqual(self.ns.failed_mc_walks, 0)

    def run_ns(self, max_iter=100, Etol=1e-4):
#        max_iter = 10000
#        self.Etol = .01
        self.Etol = Etol
        for i in xrange(int(max_iter)):
            self.ns.one_iteration()
            deltaE = self.ns.replicas[-1].energy - self.ns.replicas[0].energy
            if  deltaE < self.Etol:
                break
        self.niter = i + 1
        self.Emax = self.ns.replicas[-1].energy
        self.Emin = self.ns.replicas[0].energy
Пример #6
0
    def setUp(self):
        self.natoms = 6
        self.system = LJClusterSENS(self.natoms, 2.5)

        # create a database
        self.database = self.system.create_database()

        # add some minima to the database
        bh = self.system.get_basinhopping(self.database, outstream=None)
        while self.database.number_of_minima() < 2:
            bh.run(1)

        self.ndof = self.natoms * 3 - 6

        self.minima_searcher = _MinimaSearcher(
            self.database.minima(),
            energy_accuracy=1e-4,
            compare_structures=self.system.get_compare_exact())
Пример #7
0
def main():   
    parser = argparse.ArgumentParser(description="must pass the URI of the dispatcher")
    parser.add_argument("natoms", type=int, help="number of atoms")
    parser.add_argument("-n","--mciter", type=int, default=1000, help="number of steps in the monte carlo walk")
    parser.add_argument("--radius", type=float, default=2.5, help="maintain atoms in a sphere of this radius")
    parser.add_argument("--worker-name", type=str, help="name for the worker",default=None)
    parser.add_argument("--host", type=str, help="address of the host (node on which the worker is started)",default=None)
    parser.add_argument("--port", type=int, help="port number on which the worker is started)",default=0)
    parser.add_argument("--server-type", type=str, help="multiplex or threaded",default="multiplex")
    parser.add_argument("--dispatcherURI-addr", type=str, help=" URI for the dispatcher", default=None)
    parser.add_argument("--dispatcherURI-file", type=str, help="name of the file containing the dispatcher URI,"\
                         "by default dispatcher_uri.dat, no need to specify this option unless this changed", default=None)
    args = parser.parse_args()
    
    #===========================================================================
    # MUST SET THE SYSTEM THEN GET THE RUNNER TO PASS TO THE WORKER
    #===========================================================================
    system = LJClusterSENS(args.natoms, args.radius)
    mc_runner = system.get_mc_walker(args.mciter)
    
    dispatcher_URI_file = args.dispatcherURI_file
    dispatcher_URI_addr = args.dispatcherURI_addr
    
    if dispatcher_URI_file != None:
        with open (dispatcher_URI_file, "r") as rfile:
            dispatcher_URI = rfile.read().replace('\n', '')
    elif dispatcher_URI_addr != None:
        dispatcher_URI = dispatcher_URI_addr
    else:
        with open ("dispatcher_uri.dat", "r") as rfile:
            dispatcher_URI = rfile.read().replace('\n', '')
    
    print dispatcher_URI
    
    worker_name = args.worker_name
    host = args.host
    port = args.port
    server_type = args.server_type
    
    worker = pyro_worker(dispatcher_URI, mc_runner, worker_name=worker_name, host=host, port=port, server_type=server_type)
    worker._start_worker()
Пример #8
0
 def setUp(self):
     self.natoms = 6
     self.system = LJClusterSENS(self.natoms, 2.5)
     
     # create a database
     self.database = self.system.create_database()
     
     # add some minima to the database
     bh = self.system.get_basinhopping(self.database, outstream=None)
     while self.database.number_of_minima() < 2:
         bh.run(1)
     
     self.ndof = self.natoms * 3 - 6
 
     self.minima_searcher = _MinimaSearcher(self.database.minima(), energy_accuracy=1e-4, compare_structures=self.system.get_compare_exact())
Пример #9
0
class TestMinimaSearch(unittest.TestCase):
    def setUp(self):
        self.natoms = 6
        self.system = LJClusterSENS(self.natoms, 2.5)

        # create a database
        self.database = self.system.create_database()

        # add some minima to the database
        bh = self.system.get_basinhopping(self.database, outstream=None)
        while self.database.number_of_minima() < 2:
            bh.run(1)

        self.ndof = self.natoms * 3 - 6

        self.minima_searcher = _MinimaSearcher(
            self.database.minima(),
            energy_accuracy=1e-4,
            compare_structures=self.system.get_compare_exact())

    def test_exact(self):
        for m in self.database.minima():
            mret, tform = self.minima_searcher.get_minima(m.energy, m.coords)
            self.assertEqual(m, mret)

    def test_random(self):
        for m in self.database.minima():
            mret, tform = self.minima_searcher.get_minima(
                m.energy + np.random.uniform(-1e-4, 1e-4), m.coords)
            self.assertEqual(m, mret)

    def test_none(self):
        for m in self.database.minima():
            mret, tform = self.minima_searcher.get_minima(
                m.energy + 10., m.coords)
            self.assertIsNone(mret)
Пример #10
0
def main():
    parser = argparse.ArgumentParser(description="do nested sampling on a Lennard Jones cluster")
    parser.add_argument("natoms", type=int, help="number of atoms")
    parser.add_argument("-K", "--nreplicas", type=int, help="number of replicas", default=300)
    parser.add_argument("-n", "--mciter", type=int, default=1000, help="number of steps in the monte carlo walk")
    parser.add_argument("-P", "--nproc", type=int, help="number of processors", default=1)
    parser.add_argument("-q", action="store_true", help="turn off verbose printing of information at every step")
    parser.add_argument("--radius", type=float, default=2.5, help="maintain atoms in a sphere of this radius")
    parser.add_argument("--iprint", type=int, default=1, help="if verbose, status messages will be printed every iprint steps")
    parser.add_argument("--sens-exact", action="store_true", help="use the exact version of superposition enhanced nested sampling")
    parser.add_argument("--db", type=str, help="location of the database", default="")
    parser.add_argument("--nminima", type=int, default=-1, help="number of minima from the database to use.  If negative, use all minima")
    args = parser.parse_args()
    print args
    
    if args.sens_exact and args.db == "":
        raise Exception("for sens you must specify a database file")
    

    system = LJClusterSENS(args.natoms, args.radius)
    energy_accuracy = 1e-3

    if args.sens_exact:
        database = system.create_database(args.db, createdb=False)
        if args.nminima <= 0 or args.nminima > database.number_of_minima(): 
            minima = database.minima()
        else:
            minima = database.minima()[:args.nminima]

    
    
    mcrunner = system.get_mc_walker(args.mciter)
    nskwargs = dict(nproc=args.nproc, 
                        verbose=not args.q, iprint=args.iprint)
    
    print "mciter", args.mciter
    if args.sens_exact:
        
        ns = NestedSamplingSAExact(system, args.nreplicas, mcrunner,
                                   minima, energy_accuracy,
                                   mindist=system.get_mindist(niter=1),
                                   minimizer=system.get_minimizer(tol=1e-4),
                                   **nskwargs)
    else:
        ns = NestedSampling(system, args.nreplicas, mcrunner, 
                            **nskwargs)
    
    run_nested_sampling(ns, label="lj"+str(args.natoms), etol=1e-2)
Пример #11
0
 def set_up_system(self):
     self.natoms = 6
     self.gmin = -12.7121
     self.system = LJClusterSENS(self.natoms, 2.5)
     self.ndof = 3*self.natoms - 6
Пример #12
0
 def set_up_system(self):
     self.natoms = 13
     self.gmin = -44.3269
     self.system = LJClusterSENS(self.natoms, 2.5)
     self.ndof = 3 * self.natoms - 6
Пример #13
0
class TestNS_LJ(unittest.TestCase):
    def setUp(self):
        self.setUp1()

    def compute_cv(self, Tmin=.01, Tmax=3., nT=100):
        T = np.arange(Tmin, Tmax, (Tmax - Tmin) / nT)
        Cv = compute_cv_c(np.array(self.ns.max_energies),
                          float(self.nproc),
                          float(self.ndof),
                          T.min(),
                          T.max(),
                          T.size,
                          float(self.ndof),
                          live=False)
        return T, Cv

    def set_up_system(self):
        self.natoms = 13
        self.gmin = -44.3269
        self.system = LJClusterSENS(self.natoms, 2.5)
        self.ndof = 3 * self.natoms - 6

    def setUp1(self, nproc=1):
        self.set_up_system()
        self.nreplicas = 10
        self.stepsize = 0.01
        self.nproc = nproc

        self.mc_runner = self.system.get_mc_walker(mciter=100)

        self.ns = NestedSampling(self.system,
                                 self.nreplicas,
                                 self.mc_runner,
                                 stepsize=0.1,
                                 nproc=nproc,
                                 verbose=False)

        self.Emax0 = self.ns.replicas[-1].energy

        self.niter = 100
        for i in xrange(self.niter):
            self.ns.one_iteration()
        self.Emax = self.ns.replicas[-1].energy
        self.Emin = self.ns.replicas[0].energy

    def test1(self):
        self.assert_(len(self.ns.replicas) == self.nreplicas)
        self.assert_(self.Emax < self.Emax0)
        self.assert_(self.Emin < self.Emax)
        self.assert_(self.Emin < 0)
        self.assert_(self.Emin >= self.gmin)
        self.assert_(self.ns.stepsize != self.stepsize)
        self.assertEqual(len(self.ns.max_energies), self.niter * self.nproc)
        self.assertEqual(self.ns.failed_mc_walks, 0)

    def run_ns(self, max_iter=100, Etol=1e-4):
        #        max_iter = 10000
        #        self.Etol = .01
        self.Etol = Etol
        for i in xrange(int(max_iter)):
            self.ns.one_iteration()
            deltaE = self.ns.replicas[-1].energy - self.ns.replicas[0].energy
            if deltaE < self.Etol:
                break
        self.niter = i + 1
        self.Emax = self.ns.replicas[-1].energy
        self.Emin = self.ns.replicas[0].energy
Пример #14
0
 def set_up_system(self):
     self.natoms = 13
     self.gmin = -44.3269
     self.system = LJClusterSENS(self.natoms, 2.5)
     self.ndof = 3 * self.natoms - 6
class TestSENSExact_LJ(unittest.TestCase):
    def setUp(self):
        self.seed = np.random.randint(1000000)
#        self.seed = 549670 # failed self.assertGreater(self.ns.count_sampled_minima, 0)
        print "seed", self.seed
        np.random.seed(self.seed)
        self.setUp1()
    

    def setUp1(self, nproc=1):
        self.natoms = 31
        self.system = LJClusterSENS(self.natoms, 2.5)
        self.ndof = 3*self.natoms - 6

        self.nreplicas = 10
        self.stepsize = 0.01
        self.nproc = nproc
        
        
        try:
            self.database = self.system.create_database("/scratch/scratch2/js850/sens/testruns/lj31/lj31.sqlite", createdb=False)
        except IOError:
            self.database = build_database(self.system, 4)
            
        

        self.minima = list(self.database.minima())
        assert self.database.number_of_minima() > 1, "%d minima" %  self.database.number_of_minima()
        
        self.sampler = HSASamplerCluster(self.minima, self.ndof, copy_minima=True, 
                                         center_minima=True, 
                                         compare_structures=self.system.get_compare_exact(), 
                                         mindist=self.system.get_mindist(),
                                         minimizer=self.system.get_minimizer())

        self.Emax = min((m.energy for m in self.minima)) + 1.

        # for performing transformations like rotations, translations, permutations, etc
        self.transform = TransformAtomicCluster()
        
        # this is a list of random transformations that don't change the energy
        self.transformations = [self.rtrans, self.rrot, self.invert, self.rperm]

    def rtrans(self, x):
        vec3 = np.random.uniform(-1,1,3)
        self.transform.translate(x, vec3)
    
    def rrot(self, x):
        q = rotations.random_q()
        mx = rotations.q2mx(q)
        self.transform.rotate(x, mx)
    
    def invert(self, x):
        self.transform.invert(x)
    
    def rperm(self, x):
        perm = range(self.natoms)
        np.random.shuffle(perm)
        self.transform.permute(x, perm)
    
    def do_test(self, tform):
        # sample a configurations fr
        
        # sample a configuration from the HSA
        m, xsampled = self.sampler.sample_coords(self.Emax)
        
        # get the energy of that configuration in the HSA
        E_HSA = self.sampler.compute_energy(xsampled, m)
        
        # get the real energy of the sampled configuration
        pot = self.system.get_potential()
        Esampled = pot.getEnergy(xsampled)
        r = Replica(xsampled, Esampled)
        
        # transform xsampled in a way that preserves the real energy but not necessarily the HSA energy
        tform(xsampled)
        
        # assert the real energy has not changed
        Etrans = pot.getEnergy(xsampled)
        self.assertAlmostEqual(r.energy, Etrans, delta=1e-4)
        
        # use the nested sampling routine to compute the HSA energy of xsampled.
        # This should undo the transformations we applied and find the correct HSA energy 
        m_quench, E_HSA_computed = self.sampler.compute_energy_in_HSA(r.energy, r.x)
        
        # assert that self.ns._compute_energy_in_SA(r) was able to recover the correct HSA energy
        self.assertIsNotNone(E_HSA_computed)
        self.assertAlmostEqual(E_HSA, E_HSA_computed, delta=1e-4)
        self.assertAlmostEqual(m.energy, m_quench.energy, delta=1e-4)
        
    def fchain(self, flist):
        """return a function which applies all of the functions in flist to the input"""
        def function_chain(x):
            for f in reversed(flist):
                f(x)
        return function_chain
    
    def test1(self):
        """run do_test() on all combinations transformations"""
        for f in self.transformations:
            self.do_test(f)
    
    def test_2(self):
        """run do_test() on all combinations of length 2 of the transformations
        """
        for flist in itertools.product(self.transformations, repeat=2):
            tform = self.fchain(flist)
            self.do_test(tform)
    
    
    def test_10(self):
        """run do_test() on all combinations of length 10 of the transformations
        """
        maxiter = 500
        i = 0
        for flist in itertools.product(self.transformations, repeat=10):
            tform = self.fchain(flist)
            self.do_test(tform)
            i += 1
            if i >= maxiter: break
Пример #16
0
 def set_up_system(self):
     self.natoms = 6
     self.gmin = -12.7121
     self.system = LJClusterSENS(self.natoms, 2.5)
     self.ndof = 3 * self.natoms - 6
Пример #17
0
class TestSENSExact_LJ(_test_ns_lj.TestNS_LJ):
    def setUp(self):
        self.seed = np.random.randint(1000000)
#        self.seed = 549670 # failed self.assertGreater(self.ns.count_sampled_minima, 0)
        print "seed", self.seed
        np.random.seed(self.seed)
        self.setUp1()
    
    def set_up_system(self):
        self.natoms = 6
        self.gmin = -12.7121
        self.system = LJClusterSENS(self.natoms, 2.5)
        self.ndof = 3*self.natoms - 6


    def setUp1(self, nproc=1):
        self.set_up_system()
        self.nreplicas = 10# * nproc
        self.stepsize = 0.01
        self.nproc = nproc
        
        self.database = self.system.create_database()
        # add some minima to the database
        bh = self.system.get_basinhopping(self.database, outstream=None)
        while self.database.number_of_minima() < 2:
            bh.run(1)
        # compute the thermodynamic information
        get_thermodynamic_information(self.system, self.database)
        get_all_normalmodes(self.system, self.database)
        

        self.minima = list(self.database.minima())
        assert self.database.number_of_minima() > 1, "%d minima" %  self.database.number_of_minima()
        
        self.mc_runner = self.system.get_mc_walker(mciter=200)

        self.energy_accuracy = 1e-4
        self.hsa_sampler = HSASamplerCluster(self.minima, self.system.k, copy_minima=True, 
                                             center_minima=True, 
                                             energy_accuracy=self.energy_accuracy, 
                                             compare_structures=self.system.get_compare_exact(), 
                                             mindist=self.system.get_mindist(), 
                                             minimizer=self.system.get_minimizer(), 
                                             debug=True)

        replicas = _utils.create_replicas(self.system, self.nreplicas)
        potential = self.system.get_potential()
        potential.get_energy = potential.getEnergy
        self.ns = NestedSamplingSAExact(replicas, self.mc_runner,
                                   self.hsa_sampler, potential,
                                   config_tests=self.system.get_config_tests(),
                                   nproc=nproc, verbose=True, iprint=1, debug=True)
        
        self.Emax0 = self.ns.replicas[-1].energy
        
        self.run_ns(max_iter=1000, Etol=.001)
    

    
    def test1(self):
        super(TestSENSExact_LJ, self).test1()
        self.assertGreater(self.ns.number_swaps_accepted(), 0)
Пример #18
0
def main():
    parser = argparse.ArgumentParser(description="do nested sampling on a Lennard Jones cluster")
    parser.add_argument("natoms", type=int, help="number of atoms")
    parser.add_argument("-K", "--nreplicas", type=int, help="number of replicas", default=300)
    parser.add_argument("-n", "--mciter", type=int, default=1000, help="number of steps in the monte carlo walk")
    parser.add_argument("-P", "--nproc", type=int, help="number of processors", default=1)
    parser.add_argument("-q", action="store_true", help="turn off verbose printing of information at every step")
    parser.add_argument("--radius", type=float, default=2.5, help="maintain atoms in a sphere of this radius")
    parser.add_argument("--iprint", type=int, default=1, help="if verbose, status messages will be printed every iprint steps")
    parser.add_argument("--sens-exact", action="store_true", help="use the exact version of superposition enhanced nested sampling")
    parser.add_argument("--sens-approximate", action="store_true", help="use the approximate version of superposition enhanced nested sampling")
    parser.add_argument("--minprob", type=float, default=1., help="only for sens-approximate: probability of sampling from the database (by default <minprob>/K),"
                        "default value 1")
    parser.add_argument("--energy-offset", type=float, default=2.5, help="only for sens-approximate: value of Emax where the probabilty"
                        "starts to become non zero is <energy_max_database> + <energy_offset>")
    parser.add_argument("--db", type=str, help="location of the database", default="")
    parser.add_argument("--nminima", type=int, default=-1, help="number of minima from the database to use.  If negative, use all minima")
    parser.add_argument("--energy-onset", type=float, help="energy at which start sampling from database, by default maximum energy in database",default=None)
    parser.add_argument("--stop-crit", type=float, default=1e-3, help="run will terminate when stop_crit is larger than the difference between the maximum and minimum replica energies")
    parser.add_argument("--cpfile", type=str, help="checkpoint file name, unless renamed it takes default output name: <label>.replicas.p", default = None)
    parser.add_argument("--cpfreq", type=int, help="checkpointing frequency in number of steps", default = 10000)
    parser.add_argument("--cpstart", action="store_true", help="start calculation from checkpoint binary file")
    parser.add_argument("--dispatcherURI", action="store_true", help="use URI of the dispatcher server in default location",default=False)
    parser.add_argument("--dispatcherURI-file", type=str, help="use URI of the dispatcher server if different from default",default=None)
    args = parser.parse_args()
    print args
    
    if (args.sens_exact or args.sens_approximate) and args.db == "":
        raise Exception("for sens you must specify a database file")

    system = LJClusterSENS(args.natoms, args.radius)
    energy_accuracy = 1e-3

    if args.sens_exact or args.sens_approximate:
        database = system.create_database(args.db, createdb=False)
        if args.nminima <= 0 or args.nminima > database.number_of_minima(): 
            minima = database.minima()
        else:
            minima = database.minima()[:args.nminima]
        print "using", len(minima), "minima"
    
    if args.dispatcherURI is True:
        with open ("dispatcher_uri.dat", "r") as rfile:
            dispatcherURI = rfile.read().replace('\n', '')
    elif args.dispatcherURI_file != None:
        with open (args.dispatcherURI_file, "r") as rfile:
            dispatcherURI = rfile.read().replace('\n', '')
    else:
        dispatcherURI = None
    
    mcrunner = system.get_mc_walker(args.mciter)
    nskwargs = dict(nproc=args.nproc, verbose=not args.q,
                    iprint=args.iprint, dispatcher_URI = dispatcherURI, 
                    cpfreq = args.cpfreq, cpfile = args.cpfile,
                     cpstart = args.cpstart)
    
    # create the potential object
    potential = system.get_potential()
    potential.get_energy = potential.getEnergy

    # create the replicas
    replicas = []
    for i in xrange(args.nreplicas):
        x = system.get_random_configuration()
        e = potential.getEnergy(x)
        replicas.append(Replica(x, e))
        
        
    
    print "mciter", args.mciter
    print "radius", args.radius
    if args.sens_exact:
        hsa_sampler = HSASamplerCluster(minima, system.k, copy_minima=True, 
                center_minima=True, energy_accuracy=energy_accuracy, 
                compare_structures=system.get_compare_exact(), 
                mindist=system.get_mindist(), 
                minimizer=system.get_minimizer(), 
                debug=True)
        ns = NestedSamplingSAExact(replicas, mcrunner, hsa_sampler, potential,
                                   config_tests=system.get_config_tests(),
                                   **nskwargs)
    elif args.sens_approximate:
        ns = NestedSamplingSA(replicas, mcrunner, minima, system.k, 
                              config_tests=system.get_config_tests(),
                              minprob=args.minprob, energy_offset=args.energy_offset, 
                              energy_onset = args.energy_onset, copy_minima=True, 
                              center_minima=True, **nskwargs)
    else:
        ns = NestedSampling(replicas, mcrunner, 
                            **nskwargs)
    
    run_nested_sampling(ns, label="lj"+str(args.natoms), etol=args.stop_crit, )