Example #1
0
class Optimiser(object):

    def __init__(self, nclusters, collection, tmpdir=TMPDIR,
                 analysis='nj', initial_assignment=None, scorer=None):
        optioncheck(analysis, ANALYSES + ['tc', 'TreeCollection'])
        if self.analysis == 'tc':
            self.analysis = 'TreeCollection'
        else:
            self.analysis = analysis

        self.Collection = collection

        if not self.Collection.records[0].tree:
            print('Calculating {} trees for collection...'.format(analysis))
            self.Collection.calc_NJ_trees()

        self.datatype = collection.datatype
        if scorer is not None and isinstance(scorer, Scorer):
            self.scorer = scorer
        else:
            self.scorer = Scorer(self.Collection.records,
                                 analysis=analysis,
                                 datatype=self.datatype,
                                 tmpdir=tmpdir)

        self.nclusters = nclusters
        self.tmpdir = tmpdir

        print('Calculating initial scores...')
        if initial_assignment is None:
            initial_assignment = Partition(tuple([0]*len(collection)))
            # initial_assignment = self.random_partition(nclusters)

        self.global_best_scores = {}
        self.global_best_assignments = {}
        self.global_best_scores[self.nclusters] = self.scorer.score(
            initial_assignment, history=True)
        self.global_best_assignments[self.nclusters] = initial_assignment

        self.done_worse = 0
        self.stayed_put = 0
        self.i = 0
        self.resets = 0
        self.merges = 0

    def _reset_counts(self):
        self.done_worse = 0
        self.stayed_put = 0
        self.i = 0
        self.resets = 0

    def status(self, current_assignment, details=None):
        iter_ = self.i
        n = len(current_assignment)
        curr_score = self.scorer.score(current_assignment, history=False)
        best_score = self.global_best_scores[n]
        details = ('\t'+str(details) if details is not None else '')

        return 'Iter:{0}\tNclusters:{1}\tCurrent\tscore:{2}\tBest score:{3}{4}'.format(
            iter_, n, curr_score, best_score, details)

    def random_partition(self, nclusters):
        return Partition(tuple(np.random.randint(nclusters,
                         size=len(self.Collection))))

    def update(self, assignment):
        """
        method for working interactively and keeping nclusters correct
        """
        nclusters = len(assignment) # len(assignment) == number of clusters
        best_score = self.global_best_scores.get(nclusters, NEGINF)
        curr_score = self.scorer.score(assignment, history=False)
        if (curr_score - best_score) > EPS:
            self.global_best_assignments[nclusters] = assignment
            self.global_best_scores[nclusters] = self.scorer.score(assignment,
                history=False)

    def get_clusters(self, assignment):
        pvec = assignment.partition_vector
        index_dict = defaultdict(list)
        for (position, value) in enumerate(pvec):
            index_dict[value].append(position)
        return index_dict

    def get_cluster_trees(self, assignment, index_dict=None):
        index_dict = (index_dict or self.get_clusters(assignment))
        tree_dict = {}
        for (k, v) in index_dict.items():
            if not tuple(v) in self.scorer.concats:
                self.scorer.add(tuple(v))
            tree_dict[k] = self.scorer.concats[tuple(v)]
        return tree_dict

    def score_sample(self, sample, assignment):
        """
        !! changed to simply SCORE a PRE-MADE SAMPLE
        sample_size:int, assignment:Partition object
        Calculates score m*n score matrix, where m is number of alignments
        in the sample, and n in the number of clusters encoded in the
        assignment (==Partition object)
        """
        # sample = random.sample(range(len(self.Collection)), sample_size)
        cluster_trees = self.get_cluster_trees(assignment)
        scores = np.zeros((len(sample), len(cluster_trees)))
        for i, record_index in enumerate(sample):
            rec = self.Collection.records[record_index]
            for j, tree in cluster_trees.items():
                scores[i, j-1] = self.test(rec, tree)
        return (scores)

    def constrain_assignment(self, assignment, nclusters=None):
        """
        Constrain the assignment to have self.nclusters clusters
        """

        if nclusters is None:
            nclusters = self.nclusters
        if (nclusters < 1) or (nclusters > len(self.Collection)):
            raise ValueError('Invalid number of clusters: {}'.format(nclusters))
        while len(assignment.get_membership()) > nclusters:
            assignment = self.merge_closest(assignment)
        while len(assignment.get_membership()) < nclusters:
            assignment = self.split_search(assignment)
        return assignment

    def make_new_assignment(self, sample, scores, assignment, nreassign=1,
            choose='max'):
        """
        MAKES A NEW PARTITION BY REASSIGNING RECORDS BETWEEN CLUSTERS
        """

        new_clusters = scores.argmax(axis=1)
        M = scores/scores.sum(axis=1)[:, np.newaxis]
        if choose == 'max':
            reassignments = M.max(axis=1).argsort()[-nreassign:]
        elif choose == 'min':
            reassignments = M.min(axis=1).argsort()[:nreassign]

        new_assignment = list(assignment.partition_vector)

        for i in reassignments:
            new_assignment[sample[i]] = new_clusters[i]+1
                # because cluster number is in range
                # [1,x], and new_clusters is in range [0,x-1]

        return Partition(tuple(new_assignment))

    def move(self, sample_size, assignment, nreassign=1, choose='max',
            sampled=None):
        """
        !! now generates own sample and passes to scores
        wraps self.score_sample + self.new_assignment
        """

        if sampled is None:
            sampled = list()

        unsampled = set(range(len(self.Collection))) - set(sampled)

        if len(unsampled) > 0:
            if sample_size > len(unsampled):
                sample = unsampled
            else:
                sample = random.sample(unsampled, sample_size)

            self.sampled.extend(sample)
            scores = self.score_sample(sample, assignment)
            assignment = self.make_new_assignment(sample, scores, assignment,
                                                  nreassign, choose)
        return assignment

    def merge(self, assignment, label1, label2):
        pvec = ((x if x != label1 else label2)
                for x in assignment.partition_vector)
        return Partition(tuple(pvec))

    def merge_closest(self, assignment):
        print('Finding clusters to merge...')
        clusters = self.get_clusters(assignment)
        best_score = NEGINF
        merging = [None, None]

        for i in clusters:
            for j in clusters:
                # print('i = {}, j = {}'.format(i, j))
                if i >= j:
                    continue
                print('Testing Clusters {0} and {1}'.format(i, j))
                test_assignment = self.merge(assignment, i, j)
                self.update(test_assignment)
                score = self.scorer.score(test_assignment, history=False)

                if score > best_score:
                    merging[0] = i
                    merging[1] = j
                    best_score = score
                    best_assignment = test_assignment

        print('Merging clusters {0} and {1}'.format(*merging))
        print('Best assignment: {0}'.format(best_assignment))
        return(best_assignment)

    def split(self, k, assignment, verbosity=1):
        """
        Function to split cluster based on least representative alignment
        """
        if verbosity > 1:
            print(assignment)
        members = self.get_clusters(assignment)[k]
        if len(members) == 1:
            return assignment
        elif len(members) == 2:
            new_partition_vector = list(assignment.partition_vector)
            new_partition_vector[members[0]] = max(assignment.partition_vector) + 1
            new_assignment = Partition(new_partition_vector)
            return new_assignment

        tree = self.get_cluster_trees(assignment)[k]
        alignment_scores = {}
        if verbosity > 0:
            print('Calculating alignment scores...')

        for i in members:
            r = self.Collection.records[i]
            alignment_scores[i] = self.test(r, tree) / float(r.seqlength)
                # per-site likelihood

        seed, min_score = min(alignment_scores.iteritems(),
            key=operator.itemgetter(1))
        print('Splitting on {0}.'.format(seed+1))# convert to 1-based indexing

        new_assignment = list(assignment.partition_vector)
        new_assignment[seed] = max(assignment.partition_vector) + 1
        if verbosity > 1:
            print('New Partition: {0}'.format(new_assignment))
        if verbosity > 0:
            print('Assigning to new partition...')

        new_assignment = Partition(new_assignment)
        scores = self.score_sample(members, new_assignment)
        assignment = self.make_new_assignment(members, scores, new_assignment,
            nreassign=len(members))
        if verbosity > 1:
            print('Returning: {0}'.format(assignment))

        return assignment

    def split_max_var(self, assignment):
        clusters = self.get_clusters(assignment)
        var_dict = {}

        for k in clusters.keys():
            var_dict[k] = self.var(clusters[k])

        print(var_dict)

        cluster_to_split, var = max(clusters.iteritems(),
            key=operator.itemgetter(1))

    def split_search(self, assignment, update=True):
        clusters = self.get_clusters(assignment)
        k = len(assignment)
        best_score = NEGINF

        for i in clusters:
            print('i: {0}'.format(i))
            test_assignment = self.split(i, assignment)
            # score = self.scorer.score(test_assignment)
            if len(test_assignment) == k + 1:
                score = self.scorer.score(test_assignment, history=False)
                self.update(test_assignment)
            else:
                score = -np.Inf
                print('Something has gone wrong')
            print(test_assignment)
            print(score)

            if score > best_score:
                best_score = score
                best_assignment = test_assignment

        return best_assignment

    def test(self, record, tree, model=None):
        """
        TESTS AN ALIGNMENT AGAINST A TREE TOPOLOGY
        """
        tmp_record = copy.deepcopy(record)

        # if tree label set and record label set don't match
        header_set = set(tmp_record.headers)
        extra_in_tree = tree.labels - header_set
        extra_in_record = header_set - tree.labels

        if extra_in_tree:
            for lab in extra_in_tree:
                tmp_record.headers.append(lab)
                tmp_record.sequences.append(''.join(['-']*tmp_record.seqlength))
            tmp_record._update()

        if extra_in_record:
            for lab in extra_in_record:
                i = tmp_record.headers.index(lab)
                tmp_record.headers   = (tmp_record.headers[:i] +
                                        tmp_record.headers[i+1:])
                tmp_record.sequences = (tmp_record.sequences[:i] +
                                        tmp_record.sequences[i+1:])
            tmp_record._update()

        return tmp_alignment.likelihood(tree, self.tmpdir, fit_rates=True)
        # alignment_file = tmp_record.write_phylip('{0}/tmp_alignment.phy'.format(
        #     self.tmpdir), interleaved=True)
        # newick_file = tree.write_to_file('{0}/tmp_tree.nwk'.format(self.tmpdir))
        # p = Phyml(tmp_record, self.tmpdir)
        # p.add_tempfile(alignment_file)
        # p.add_tempfile(newick_file)
        # p.add_flag('-i', alignment_file)
        # p.add_flag('-u', newick_file)
        # p.add_flag('-b', '0')    # no bootstraps
        # if tmp_record.datatype == 'dna':
        #     if model is None:
        #         model = 'GTR'
        #     p.add_flag('-m', model)
        #     p.add_flag('-d', 'nt')
        # else:
        #     if model is None:
        #         model = 'WAG'
        #     p.add_flag('-m', model)  # evolutionary model
        #     p.add_flag('-d', 'aa')   # datatype

        # p.add_flag('-o', 'n')    # no optimisation
        # return p.run().score

    def var(self, members):
        score = self.scorer.add(tuple(members)).score
        records = [self.Collection.records[i] for i in members]
        total_length = sum([r.seqlength for r in records])

        return(score / total_length)

    def optimise(self,
                 assignment,
                 nclusters=None,
                 update=True,
                 history=True,
                 sample_size=10,
                 nreassign=10,
                 max_stayed_put=25,
                 max_resets=5,
                 max_done_worse=5,
                 max_iter=1000):

        if nclusters is None:
            nclusters = self.nclusters

        assignment = self.constrain_assignment(assignment, nclusters)

        local_best_assignment = assignment
        local_best_score = self.scorer.score(local_best_assignment,
            history=False)
        current_assignment = local_best_assignment
        self.sampled = []

        print(self.status(current_assignment))

        while True:
            if self.stayed_put > max_stayed_put:
                print('stayed put too many times ({0})'.format(max_stayed_put))
                break
            if self.resets == max_resets:
                print('Reset limit reached ({0})'.format(max_resets))
                break
            if self.done_worse == max_done_worse:
                print('wandered off, resetting...')
                self.resets += 1
                self.done_worse = 0
                current_assignment = local_best_assignment
            if self.i == max_iter:
                print('max iterations reached')
                break

            new_assignment = self.move(sample_size, current_assignment,
                                       nreassign)
            new_assignment = self.constrain_assignment(new_assignment,
                nclusters)
            score = self.scorer.score(new_assignment, history=history)
            self.update(new_assignment)

            if (score - local_best_score) > EPS:
                self.sampled = []
                local_best_score = score
                local_best_assignment = new_assignment
                self.stayed_put = 0
                self.done_worse = 0
                self.resets = 0
                print(self.status(new_assignment, '(Improved)'))
            elif np.abs(score - local_best_score) < EPS:
                self.stayed_put += 1
                self.done_worse = 0
                message = ('(No improvement - [{}/{}])'.format(self.stayed_put,
                                                               max_stayed_put))
                print(self.status(new_assignment, message))
            else:
                self.sampled = []
                #self.stayed_put = 0
                self.done_worse += 1
                message = '(Did worse - [{}/{}]'.format(self.done_worse,
                                                        max_done_worse)
                print(self.status(new_assignment, message))

            self.i += 1

        self._reset_counts()
        return local_best_assignment

    def optimise_with_variable_clusters(self,
            assignment,
            target_clusters,
            max_clusters,
            optimise_on_ascent=True,
            optimise_on_descent=True,
            update=True,
            **kwargs):

        if max_clusters < target_clusters:
            raise ValueError('max_clusters ({}) must be at least equal to '
                'target_clusters ({})'.format(max_clusters, target_clusters))

        current_clusters = len(assignment)
        print('Optimising current assignment with {} clusters. Optimiser will '
              'ascend to {} clusters, and descend to a target of {} clusters'
              '.'.format(current_clusters, max_clusters, target_clusters))
        for n in range(current_clusters, max_clusters+1):
            print("ASCENDING (optimisation:{}) -> Current target: "
                  "{} clusters".format(('ON' if optimise_on_ascent else 'OFF'),
                                       n))
            if optimise_on_ascent:
                assignment = self.optimise(assignment, nclusters=n, **kwargs)
            else:
                assignment = self.constrain_assignment(assignment, n)

        for n in range(max_clusters-1, target_clusters-1, -1):
            print('DESCENDING (optimisation:{}) -> Current target: {} '
                  'clusters'.format(('ON' if optimise_on_descent else 'OFF'),
                                    n))
            if optimise_on_descent:
                assignment = self.optimise(assignment, nclusters=n, **kwargs)
            else:
                assignment = self.constrain_assignment(assignment, n)

        return self.constrain_assignment(assignment, target_clusters)

    def write(self, filename):
        headers = ['Iteration', 'CPU Time', 'Likelihood', 'Partition',
                   'NClusters']
        output = [[i] + x + len(x[-1])
                    for (i, x) in enumerate(self.scorer.history)]

        with open(filename, 'w+') as file_:
            writer = csv.writer(file_, delimiter='\t', quoting=csv.QUOTE_NONE)
            writer.writerow(headers)
            writer.writerows(output)
Example #2
0
class Optimiser(object):
    def __init__(self, nclusters, collection, tmpdir=TMPDIR,
                 analysis='nj', initial_assignment=None, scorer=None):
        optioncheck(analysis, ANALYSES + ['tc', 'TreeCollection'])
        if self.analysis == 'tc':
            self.analysis = 'TreeCollection'
        else:
            self.analysis = analysis

        self.Collection = collection

        if not self.Collection.records[0].tree:
            print('Calculating {} trees for collection...'.format(analysis))
            self.Collection.calc_NJ_trees()

        self.datatype = collection.datatype
        if scorer is not None and isinstance(scorer, Scorer):
            self.scorer = scorer
        else:
            self.scorer = Scorer(self.Collection)

        self.nclusters = nclusters
        self.tmpdir = tmpdir

        print('Calculating initial scores...')
        if initial_assignment is None:
            initial_assignment = Partition(tuple([0] * len(collection)))
            # initial_assignment = self.random_partition(nclusters)

        self.global_best_scores = {}
        self.global_best_assignments = {}
        self.global_best_scores[self.nclusters] = self.scorer.score(
            initial_assignment, history=True)
        self.global_best_assignments[self.nclusters] = initial_assignment

        self.done_worse = 0
        self.stayed_put = 0
        self.i = 0
        self.resets = 0
        self.merges = 0

    def _reset_counts(self):
        self.done_worse = 0
        self.stayed_put = 0
        self.i = 0
        self.resets = 0

    def status(self, current_assignment, details=None):
        iter_ = self.i
        n = len(current_assignment)
        curr_score = self.scorer.score(current_assignment, history=False)
        best_score = self.global_best_scores[n]
        details = ('\t' + str(details) if details is not None else '')

        return 'Iter:{0}\tNclusters:{1}\tCurrent\tscore:{2}\tBest score:{3}{4}'.format(
            iter_, n, curr_score, best_score, details)

    def random_partition(self, nclusters):
        return Partition(tuple(np.random.randint(nclusters,
                                                 size=len(self.Collection))))

    def update(self, assignment):
        """
        method for working interactively and keeping nclusters correct
        """
        nclusters = len(assignment)  # len(assignment) == number of clusters
        best_score = self.global_best_scores.get(nclusters, NEGINF)
        curr_score = self.scorer.score(assignment, history=False)
        if (curr_score - best_score) > EPS:
            self.global_best_assignments[nclusters] = assignment
            self.global_best_scores[nclusters] = self.scorer.score(assignment,
                                                                   history=False)

    def get_cluster_trees(self, assignment, index_dict=None):
        index_dict = (index_dict or get_clusters(assignment))
        tree_dict = {}
        for (k, v) in index_dict.items():
            if not tuple(v) in self.scorer.concats:
                self.scorer.add(tuple(v))
            tree_dict[k] = self.scorer.concats[tuple(v)]
        return tree_dict

    def score_sample(self, sample, assignment):
        """
        !! changed to simply SCORE a PRE-MADE SAMPLE
        sample_size:int, assignment:Partition object
        Calculates score m*n score matrix, where m is number of alignments
        in the sample, and n in the number of clusters encoded in the
        assignment (==Partition object)
        """
        # sample = random.sample(range(len(self.Collection)), sample_size)
        cluster_trees = self.get_cluster_trees(assignment)
        scores = np.zeros((len(sample), len(cluster_trees)))
        for i, record_index in enumerate(sample):
            rec = self.Collection.records[record_index]
            for j, tree in cluster_trees.items():
                scores[i, j - 1] = self.test(rec, tree)
        return scores

    def constrain_assignment(self, assignment, nclusters=None):
        """
        Constrain the assignment to have self.nclusters clusters
        """

        if nclusters is None:
            nclusters = self.nclusters
        if (nclusters < 1) or (nclusters > len(self.Collection)):
            raise ValueError('Invalid number of clusters: {}'.format(nclusters))
        while len(assignment.get_membership()) > nclusters:
            assignment = self.merge_closest(assignment)
        while len(assignment.get_membership()) < nclusters:
            assignment = self.split_search(assignment)
        return assignment

    def make_new_assignment(self, sample, scores, assignment, nreassign=1,
                            choose='max'):
        """
        MAKES A NEW PARTITION BY REASSIGNING RECORDS BETWEEN CLUSTERS
        """
        optioncheck(choose, ('max', 'min'))
        new_clusters = scores.argmax(axis=1)
        M = scores / scores.sum(axis=1)[:, np.newaxis]
        if choose == 'max':
            reassignments = M.max(axis=1).argsort()[-nreassign:]
        else:
            reassignments = M.min(axis=1).argsort()[:nreassign]

        new_assignment = list(assignment.partition_vector)

        for i in reassignments:
            new_assignment[sample[i]] = new_clusters[i] + 1
            # because cluster number is in range
            # [1,x], and new_clusters is in range [0,x-1]

        return Partition(tuple(new_assignment))

    def move(self, sample_size, assignment, nreassign=1, choose='max',
             sampled=None):
        """
        !! now generates own sample and passes to scores
        wraps self.score_sample + self.new_assignment
        """

        if sampled is None:
            sampled = list()

        unsampled = set(range(len(self.Collection))) - set(sampled)

        if len(unsampled) > 0:
            if sample_size > len(unsampled):
                sample = unsampled
            else:
                sample = random.sample(unsampled, sample_size)

            self.sampled.extend(sample)
            scores = self.score_sample(sample, assignment)
            assignment = self.make_new_assignment(sample, scores, assignment,
                                                  nreassign, choose)
        return assignment

    def merge(self, assignment, label1, label2):
        pvec = ((x if x != label1 else label2)
                for x in assignment.partition_vector)
        return Partition(tuple(pvec))

    def merge_closest(self, assignment):
        print('Finding clusters to merge...')
        clusters = get_clusters(assignment)
        best_score = NEGINF
        merging = [None, None]

        for i in clusters:
            for j in clusters:
                # print('i = {}, j = {}'.format(i, j))
                if i >= j:
                    continue
                print('Testing Clusters {0} and {1}'.format(i, j))
                test_assignment = self.merge(assignment, i, j)
                self.update(test_assignment)
                score_value = self.scorer.score(test_assignment, history=False)

                if score_value > best_score:
                    merging[0] = i
                    merging[1] = j
                    best_score = score_value
                    best_assignment = test_assignment

        print('Merging clusters {0} and {1}'.format(*merging))
        print('Best assignment: {0}'.format(best_assignment))
        return best_assignment

    def split(self, k, assignment, verbosity=1):
        """
        Function to split cluster based on least representative alignment
        """
        if verbosity > 1:
            print(assignment)
        members = get_clusters(assignment)[k]
        if len(members) == 1:
            return assignment
        elif len(members) == 2:
            new_partition_vector = list(assignment.partition_vector)
            new_partition_vector[members[0]] = max(assignment.partition_vector) + 1
            new_assignment = Partition(new_partition_vector)
            return new_assignment

        tree = self.get_cluster_trees(assignment)[k]
        alignment_scores = {}
        if verbosity > 0:
            print('Calculating alignment scores...')

        for i in members:
            r = self.Collection.records[i]
            alignment_scores[i] = self.test(r, tree) / float(r.seqlength)
            # per-site likelihood

        seed, min_score = min(alignment_scores.iteritems(),
                              key=operator.itemgetter(1))
        print('Splitting on {0}.'.format(seed + 1))  # convert to 1-based indexing

        new_assignment = list(assignment.partition_vector)
        new_assignment[seed] = max(assignment.partition_vector) + 1
        if verbosity > 1:
            print('New Partition: {0}'.format(new_assignment))
        if verbosity > 0:
            print('Assigning to new partition...')

        new_assignment = Partition(new_assignment)
        scores = self.score_sample(members, new_assignment)
        assignment = self.make_new_assignment(members, scores, new_assignment,
                                              nreassign=len(members))
        if verbosity > 1:
            print('Returning: {0}'.format(assignment))

        return assignment

    def split_max_var(self, assignment):
        clusters = get_clusters(assignment)
        var_dict = {}

        for k in clusters.keys():
            var_dict[k] = self.var(clusters[k])

        print(var_dict)

        cluster_to_split, var = max(clusters.iteritems(),
                                    key=operator.itemgetter(1))

    def split_search(self, assignment, update=True):
        clusters = get_clusters(assignment)
        k = len(assignment)
        best_score = NEGINF

        for i in clusters:
            print('i: {0}'.format(i))
            test_assignment = self.split(i, assignment)
            # score = self.scorer.score(test_assignment)
            if len(test_assignment) == k + 1:
                curr_score = self.scorer.score(test_assignment, history=False)
                self.update(test_assignment)
            else:
                curr_score = -np.Inf
                print('Something has gone wrong')
            print(test_assignment)
            print(curr_score)

            if curr_score > best_score:
                best_score = curr_score
                best_assignment = test_assignment

        return best_assignment

    def test(self, record, tree, model=None):
        """
        TESTS AN ALIGNMENT AGAINST A TREE TOPOLOGY
        """
        tmp_record = copy.deepcopy(record)

        # if tree label set and record label set don't match
        header_set = set(tmp_record.headers)
        extra_in_tree = tree.labels - header_set
        extra_in_record = header_set - tree.labels

        if extra_in_tree:
            for lab in extra_in_tree:
                tmp_record.headers.append(lab)
                tmp_record.sequences.append(''.join(['-'] * tmp_record.seqlength))
            tmp_record.update()

        if extra_in_record:
            for lab in extra_in_record:
                i = tmp_record.headers.index(lab)
                tmp_record.headers = (tmp_record.headers[:i] +
                                      tmp_record.headers[i + 1:])
                tmp_record.sequences = (tmp_record.sequences[:i] +
                                        tmp_record.sequences[i + 1:])
            tmp_record.update()

        return tmp_alignment.likelihood(tree, self.tmpdir, fit_rates=True)
        # alignment_file = tmp_record.write_phylip('{0}/tmp_alignment.phy'.format(
        # self.tmpdir), interleaved=True)
        # newick_file = tree.write_to_file('{0}/tmp_tree.nwk'.format(self.tmpdir))
        # p = Phyml(tmp_record, self.tmpdir)
        # p.add_tempfile(alignment_file)
        # p.add_tempfile(newick_file)
        # p.add_flag('-i', alignment_file)
        # p.add_flag('-u', newick_file)
        # p.add_flag('-b', '0')    # no bootstraps
        # if tmp_record.datatype == 'dna':
        #     if model is None:
        #         model = 'GTR'
        #     p.add_flag('-m', model)
        #     p.add_flag('-d', 'nt')
        # else:
        #     if model is None:
        #         model = 'WAG'
        #     p.add_flag('-m', model)  # evolutionary model
        #     p.add_flag('-d', 'aa')   # datatype

        # p.add_flag('-o', 'n')    # no optimisation
        # return p.run().score

    def var(self, members):
        score = self.scorer.add(tuple(members)).score
        records = [self.Collection.records[i] for i in members]
        total_length = sum([r.seqlength for r in records])

        return score / total_length

    def optimise(self,
                 assignment,
                 nclusters=None,
                 update=True,
                 history=True,
                 sample_size=10,
                 nreassign=10,
                 max_stayed_put=25,
                 max_resets=5,
                 max_done_worse=5,
                 max_iter=1000):

        if nclusters is None:
            nclusters = self.nclusters

        assignment = self.constrain_assignment(assignment, nclusters)

        local_best_assignment = assignment
        local_best_score = self.scorer.score(local_best_assignment,
                                             history=False)
        current_assignment = local_best_assignment
        self.sampled = []

        print(self.status(current_assignment))

        while True:
            if self.stayed_put > max_stayed_put:
                print('stayed put too many times ({0})'.format(max_stayed_put))
                break
            if self.resets == max_resets:
                print('Reset limit reached ({0})'.format(max_resets))
                break
            if self.done_worse == max_done_worse:
                print('wandered off, resetting...')
                self.resets += 1
                self.done_worse = 0
                current_assignment = local_best_assignment
            if self.i == max_iter:
                print('max iterations reached')
                break

            new_assignment = self.move(sample_size, current_assignment,
                                       nreassign)
            new_assignment = self.constrain_assignment(new_assignment,
                                                       nclusters)
            score = self.scorer.score(new_assignment, history=history)
            self.update(new_assignment)

            if (score - local_best_score) > EPS:
                self.sampled = []
                local_best_score = score
                local_best_assignment = new_assignment
                self.stayed_put = 0
                self.done_worse = 0
                self.resets = 0
                print(self.status(new_assignment, '(Improved)'))
            elif np.abs(score - local_best_score) < EPS:
                self.stayed_put += 1
                self.done_worse = 0
                message = ('(No improvement - [{}/{}])'.format(self.stayed_put,
                                                               max_stayed_put))
                print(self.status(new_assignment, message))
            else:
                self.sampled = []
                # self.stayed_put = 0
                self.done_worse += 1
                message = '(Did worse - [{}/{}]'.format(self.done_worse,
                                                        max_done_worse)
                print(self.status(new_assignment, message))

            self.i += 1

        self._reset_counts()
        return local_best_assignment

    def optimise_with_variable_clusters(self,
                                        assignment,
                                        target_clusters,
                                        max_clusters,
                                        optimise_on_ascent=True,
                                        optimise_on_descent=True,
                                        update=True,
                                        **kwargs):

        if max_clusters < target_clusters:
            raise ValueError('max_clusters ({}) must be at least equal to '
                             'target_clusters ({})'.format(max_clusters, target_clusters))

        current_clusters = len(assignment)
        print('Optimising current assignment with {} clusters. Optimiser will '
              'ascend to {} clusters, and descend to a target of {} clusters'
              '.'.format(current_clusters, max_clusters, target_clusters))
        for n in range(current_clusters, max_clusters + 1):
            print("ASCENDING (optimisation:{}) -> Current target: "
                  "{} clusters".format(('ON' if optimise_on_ascent else 'OFF'),
                                       n))
            if optimise_on_ascent:
                assignment = self.optimise(assignment, nclusters=n, **kwargs)
            else:
                assignment = self.constrain_assignment(assignment, n)

        for n in range(max_clusters - 1, target_clusters - 1, -1):
            print('DESCENDING (optimisation:{}) -> Current target: {} '
                  'clusters'.format(('ON' if optimise_on_descent else 'OFF'),
                                    n))
            if optimise_on_descent:
                assignment = self.optimise(assignment, nclusters=n, **kwargs)
            else:
                assignment = self.constrain_assignment(assignment, n)

        return self.constrain_assignment(assignment, target_clusters)

    def write(self, filename):
        headers = ['Iteration', 'CPU Time', 'Likelihood', 'Partition',
                   'NClusters']
        output = [[i] + x + len(x[-1])
                  for (i, x) in enumerate(self.scorer.history)]

        with open(filename, 'w+') as file_:
            writer = csv.writer(file_, delimiter='\t', quoting=csv.QUOTE_NONE)
            writer.writerow(headers)
            writer.writerows(output)
Example #3
0
class Cluster(object):
    def __init__(self, members, records, analysis):
        self.members = tuple(members)
        self.records = [records[i] for i in self.members]
        self.scorer = Scorer(records, analysis)
        self.tree = self.scorer.add(self.members)
Example #4
0
class Cluster(object):
    def __init__(self, members, records, analysis):
        self.members = tuple(members)
        self.records = [records[i] for i in self.members]
        self.scorer = Scorer(records, analysis)
        self.tree = self.scorer.add(self.members)