
# This file is part of PyEMMA.
#
# Copyright (c) 2015, 2014 Computational Molecular Biology Group, Freie Universitaet Berlin (GER)
#
# PyEMMA is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
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# You should have received a copy of the GNU Lesser General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.


r"""Unit test for Chapman-Kolmogorov-Test module

.. moduleauthor:: B.Trendelkamp-Schroer <benjamin DOT trendelkamp-schroer AT fu-berlin DOT de>

"""

from __future__ import absolute_import
import unittest

import numpy as np

from pyemma import msm
from msmtools.generation import generate_traj
from msmtools.estimation import count_matrix, largest_connected_set, largest_connected_submatrix, transition_matrix
from pyemma.util.numeric import assert_allclose
from pyemma.msm.tests.birth_death_chain import BirthDeathChain
from pyemma.msm import estimate_markov_model
from six.moves import range

import sys
on_win = sys.platform == 'win32'


class TestCK_MSM(unittest.TestCase):
    def setUp(self):
        """Store state of the rng"""
        self.state = np.random.mtrand.get_state()

        """Reseed the rng to enforce 'deterministic' behavior"""
        np.random.mtrand.seed(42)

        """Meta-stable birth-death chain"""
        b = 2
        q = np.zeros(7)
        p = np.zeros(7)
        q[1:] = 0.5
        p[0:-1] = 0.5
        q[2] = 1.0 - 10 ** (-b)
        q[4] = 10 ** (-b)
        p[2] = 10 ** (-b)
        p[4] = 1.0 - 10 ** (-b)

        bdc = BirthDeathChain(q, p)
        P = bdc.transition_matrix()
        dtraj = generate_traj(P, 10000, start=0)
        tau = 1

        """Estimate MSM"""
        MSM = estimate_markov_model(dtraj, tau)
        C_MSM = MSM.count_matrix_full
        lcc_MSM = MSM.largest_connected_set
        Ccc_MSM = MSM.count_matrix_active
        P_MSM = MSM.transition_matrix
        mu_MSM = MSM.stationary_distribution

        """Meta-stable sets"""
        A = [0, 1, 2]
        B = [4, 5, 6]

        w_MSM = np.zeros((2, mu_MSM.shape[0]))
        w_MSM[0, A] = mu_MSM[A] / mu_MSM[A].sum()
        w_MSM[1, B] = mu_MSM[B] / mu_MSM[B].sum()

        K = 10
        P_MSM_dense = P_MSM

        p_MSM = np.zeros((K, 2))
        w_MSM_k = 1.0 * w_MSM
        for k in range(1, K):
            w_MSM_k = np.dot(w_MSM_k, P_MSM_dense)
            p_MSM[k, 0] = w_MSM_k[0, A].sum()
            p_MSM[k, 1] = w_MSM_k[1, B].sum()

        """Assume that sets are equal, A(\tau)=A(k \tau) for all k"""
        w_MD = 1.0 * w_MSM
        p_MD = np.zeros((K, 2))
        eps_MD = np.zeros((K, 2))
        p_MSM[0, :] = 1.0
        p_MD[0, :] = 1.0
        eps_MD[0, :] = 0.0
        for k in range(1, K):
            """Build MSM at lagtime k*tau"""
            C_MD = count_matrix(dtraj, k * tau, sliding=True) / (k * tau)
            lcc_MD = largest_connected_set(C_MD)
            Ccc_MD = largest_connected_submatrix(C_MD, lcc=lcc_MD)
            c_MD = Ccc_MD.sum(axis=1)
            P_MD = transition_matrix(Ccc_MD).toarray()
            w_MD_k = np.dot(w_MD, P_MD)

            """Set A"""
            prob_MD = w_MD_k[0, A].sum()
            c = c_MD[A].sum()
            p_MD[k, 0] = prob_MD
            eps_MD[k, 0] = np.sqrt(k * (prob_MD - prob_MD ** 2) / c)

            """Set B"""
            prob_MD = w_MD_k[1, B].sum()
            c = c_MD[B].sum()
            p_MD[k, 1] = prob_MD
            eps_MD[k, 1] = np.sqrt(k * (prob_MD - prob_MD ** 2) / c)

        """Input"""
        self.MSM = MSM
        self.K = K
        self.A = A
        self.B = B

        """Expected results"""
        self.p_MSM = p_MSM
        self.p_MD = p_MD
        self.eps_MD = eps_MD

    def tearDown(self):
        """Revert the state of the rng"""
        np.random.mtrand.set_state(self.state)

    def test_cktest_njobs_1(self):
        # introduce a (fake) third set in order to model incomplete partition.
        memberships = np.array([[1, 0, 0],
                                [1, 0, 0],
                                [1, 0, 0],
                                [0, 1, 0],
                                [0, 0, 1],
                                [0, 0, 1],
                                [0, 0, 1]])
        ck = self.MSM.cktest(3, memberships=memberships, n_jobs=1)
        p_MSM = np.vstack([ck.predictions[:, 0, 0], ck.predictions[:, 2, 2]]).T
        assert_allclose(p_MSM, self.p_MSM)
        p_MD = np.vstack([ck.estimates[:, 0, 0], ck.estimates[:, 2, 2]]).T
        assert_allclose(p_MD, self.p_MD)

    @unittest.skipIf(on_win, "known to fail for pytest issue")
    def test_cktest_njobs_2(self):
        # introduce a (fake) third set in order to model incomplete partition.
        memberships = np.array([[1, 0, 0],
                                [1, 0, 0],
                                [1, 0, 0],
                                [0, 1, 0],
                                [0, 0, 1],
                                [0, 0, 1],
                                [0, 0, 1]])
        ck = self.MSM.cktest(3, memberships=memberships, n_jobs=2)
        p_MSM = np.vstack([ck.predictions[:, 0, 0], ck.predictions[:, 2, 2]]).T
        assert_allclose(p_MSM, self.p_MSM)
        p_MD = np.vstack([ck.estimates[:, 0, 0], ck.estimates[:, 2, 2]]).T
        assert_allclose(p_MD, self.p_MD)

    @unittest.skipIf(on_win, "known to fail for pytest issue")
    def test_cktest_njobs_3(self):
        # introduce a (fake) third set in order to model incomplete partition.
        memberships = np.array([[1, 0, 0],
                                [1, 0, 0],
                                [1, 0, 0],
                                [0, 1, 0],
                                [0, 0, 1],
                                [0, 0, 1],
                                [0, 0, 1]])
        ck = self.MSM.cktest(3, memberships=memberships, n_jobs=3)
        p_MSM = np.vstack([ck.predictions[:, 0, 0], ck.predictions[:, 2, 2]]).T
        assert_allclose(p_MSM, self.p_MSM)
        p_MD = np.vstack([ck.estimates[:, 0, 0], ck.estimates[:, 2, 2]]).T
        assert_allclose(p_MD, self.p_MD)


class TestCK_AllEstimators(unittest.TestCase):
    """ Integration tests for various estimators
    """

    @classmethod
    def setUpClass(cls):
        # load double well data
        import pyemma.datasets
        cls.double_well_data = pyemma.datasets.load_2well_discrete()

    def test_ck_msm(self):
        MLMSM = msm.estimate_markov_model([self.double_well_data.dtraj_T100K_dt10_n6good], 40)
        ck = MLMSM.cktest(2, mlags=[0,1,10])
        estref = np.array([[[ 1.,          0.        ],
                            [ 0.,          1.        ]],
                           [[ 0.89806859,  0.10193141],
                            [ 0.10003466,  0.89996534]],
                           [[ 0.64851782,  0.35148218],
                            [ 0.34411751,  0.65588249]]])
        predref = np.array([[[ 1.,          0.        ],
                             [ 0.,          1.        ]],
                            [[ 0.89806859,  0.10193141],
                             [ 0.10003466,  0.89996534]],
                            [[ 0.62613723,  0.37386277],
                             [ 0.3669059,   0.6330941 ]]])
        # rough agreement with MLE
        assert np.allclose(ck.estimates, estref, rtol=0.1, atol=10.0)
        assert ck.estimates_conf[0] is None
        assert ck.estimates_conf[1] is None
        assert np.allclose(ck.predictions, predref, rtol=0.1, atol=10.0)
        assert ck.predictions_conf[0] is None
        assert ck.predictions_conf[1] is None

    def test_its_bmsm(self):
        BMSM = msm.bayesian_markov_model([self.double_well_data.dtraj_T100K_dt10_n6good], 40, reversible=True)
        # also ensure that reversible bit does not flip during cktest
        assert BMSM.reversible
        ck = BMSM.cktest(2, mlags=[0,1,10])
        assert BMSM.reversible
        estref = np.array([[[ 1.,          0.        ],
                            [ 0.,          1.        ]],
                           [[ 0.89722931,  0.10277069],
                            [ 0.10070029,  0.89929971]],
                           [[ 0.64668027,  0.35331973],
                            [ 0.34369109,  0.65630891]]])
        predref = np.array([[[ 1.,          0.        ],
                             [ 0.,          1.        ]],
                            [[ 0.89722931,  0.10277069],
                             [ 0.10070029,  0.89929971]],
                            [[ 0.62568693,  0.37431307],
                             [ 0.36677222,  0.63322778]]])
        predLref = np.array([[[ 1.        ,  0.        ],
                              [ 0.        ,  1.        ]],
                             [[ 0.89398296,  0.09942586],
                              [ 0.09746008,  0.89588256]],
                             [[ 0.6074675 ,  0.35695492],
                              [ 0.34831224,  0.61440531]]])
        predRref = np.array([[[ 1.        ,  0.        ],
                              [ 0.        ,  1.        ]],
                             [[ 0.90070139,  0.10630301],
                              [ 0.10456111,  0.90255169]],
                             [[ 0.64392557,  0.39258944],
                              [ 0.38762444,  0.65176265]]])
        # rough agreement
        assert np.allclose(ck.estimates, estref, rtol=0.1, atol=10.0)
        assert ck.estimates_conf[0] is None
        assert ck.estimates_conf[1] is None
        assert np.allclose(ck.predictions, predref, rtol=0.1, atol=10.0)
        assert np.allclose(ck.predictions[0], predLref, rtol=0.1, atol=10.0)
        assert np.allclose(ck.predictions[1], predRref, rtol=0.1, atol=10.0)

    def test_its_hmsm(self):
        MLHMM = msm.estimate_hidden_markov_model([self.double_well_data.dtraj_T100K_dt10_n6good], 2, 10)
        ck = MLHMM.cktest(mlags=[0,1,10])
        estref = np.array([[[ 1.,          0.        ],
                            [ 0.,          1.        ]],
                           [[ 0.98515058,  0.01484942],
                            [ 0.01442843,  0.98557157]],
                           [[ 0.88172685,  0.11827315],
                            [ 0.11878823,  0.88121177]]])
        predref = np.array([[[ 1.,          0.        ],
                             [ 0.,          1.        ]],
                            [[ 0.98515058,  0.01484942],
                             [ 0.01442843,  0.98557157]],
                            [[ 0.86961812,  0.13038188],
                             [ 0.12668553,  0.87331447]]])
        # rough agreement with MLE
        assert np.allclose(ck.estimates, estref, rtol=0.1, atol=10.0)
        assert ck.estimates_conf[0] is None
        assert ck.estimates_conf[1] is None
        assert np.allclose(ck.predictions, predref, rtol=0.1, atol=10.0)
        assert ck.predictions_conf[0] is None
        assert ck.predictions_conf[1] is None

    def test_its_bhmm(self):
        BHMM = msm.bayesian_hidden_markov_model([self.double_well_data.dtraj_T100K_dt10_n6good], 2, 10)
        ck = BHMM.cktest(mlags=[0,1,10])
        estref = np.array([[[ 1.,          0.        ],
                            [ 0.,          1.        ]],
                           [[ 0.98497185,  0.01502815],
                            [ 0.01459256,  0.98540744]],
                           [[ 0.88213404,  0.11786596],
                            [ 0.11877379,  0.88122621]]])
        predref = np.array([[[ 1.,          0.        ],
                             [ 0.,          1.        ]],
                            [[ 0.98497185,  0.01502815],
                             [ 0.01459256,  0.98540744]],
                            [[ 0.86824695,  0.13175305],
                             [ 0.1279342,   0.8720658 ]]])
        predLref = np.array([[[ 1.        ,  0.        ],
                              [ 0.        ,  1.        ]],
                             [[ 0.98282734,  0.01284444],
                              [ 0.0123793 ,  0.98296742]],
                             [[ 0.8514399 ,  0.11369687],
                              [ 0.10984971,  0.85255827]]])
        predRref = np.array([[[ 1.        ,  0.        ],
                              [ 0.        ,  1.        ]],
                             [[ 0.98715575,  0.01722138],
                              [ 0.0178059 ,  0.98762081]],
                             [[ 0.8865478 ,  0.14905352],
                              [ 0.14860461,  0.89064809]]])
        # rough agreement
        assert np.allclose(ck.estimates, estref, rtol=0.1, atol=10.0)
        assert ck.estimates_conf[0] is None
        assert ck.estimates_conf[1] is None
        assert np.allclose(ck.predictions, predref, rtol=0.1, atol=10.0)
        assert np.allclose(ck.predictions[0], predLref, rtol=0.1, atol=10.0)
        assert np.allclose(ck.predictions[1], predRref, rtol=0.1, atol=10.0)


if __name__ == "__main__":
    unittest.main()