1#! /usr/bin/env python
2# -*- coding: utf-8 -*-
3
4##############################################################################
5##  DendroPy Phylogenetic Computing Library.
6##
7##  Copyright 2010-2015 Jeet Sukumaran and Mark T. Holder.
8##  All rights reserved.
9##
10##  See "LICENSE.rst" for terms and conditions of usage.
11##
12##  If you use this work or any portion thereof in published work,
13##  please cite it as:
14##
15##     Sukumaran, J. and M. T. Holder. 2010. DendroPy: a Python library
16##     for phylogenetic computing. Bioinformatics 26: 1569-1571.
17##
18##############################################################################
19
20"""
21Classes and Methods for working with tree reconciliation, fitting, embedding,
22contained/containing etc.
23"""
24
25import dendropy
26from dendropy.model import coalescent
27
28class ContainingTree(dendropy.Tree):
29    """
30    A "containing tree" is a (usually rooted) tree data structure within which
31    other trees are "contained". For example, species trees and their contained
32    gene trees; host trees and their contained parasite trees; biogeographical
33    "area" trees and their contained species or taxon trees.
34    """
35
36    def __init__(self,
37            containing_tree,
38            contained_taxon_namespace,
39            contained_to_containing_taxon_map,
40            contained_trees=None,
41            fit_containing_edge_lengths=True,
42            collapse_empty_edges=True,
43            ultrametricity_precision=False,
44            ignore_root_deep_coalescences=True,
45            **kwargs):
46        """
47        __init__ converts ``self`` to ContainingTree class, embedding the trees
48        given in the list, ``contained_trees.``
49
50
51        Mandatory Arguments:
52
53            ``containing_tree``
54                A |Tree| or |Tree|-like object that describes the topological
55                constraints or conditions of the containing tree (e.g., species,
56                host, or biogeographical area trees).
57
58            ``contained_taxon_namespace``
59                A |TaxonNamespace| object that will be used to manage the taxa of
60                the contained trees.
61
62            ``contained_to_containing_taxon_map``
63                A |TaxonNamespaceMapping| object mapping |Taxon| objects in the
64                contained |TaxonNamespace| to corresponding |Taxon| objects in the
65                containing tree.
66
67        Optional Arguments:
68
69            ``contained_trees``
70                An iterable container of |Tree| or |Tree|-like objects that
71                will be contained into ``containing_tree``; e.g. gene or
72                parasite trees.
73
74            ``fit_containing_edge_lengths``
75                If |True| [default], then the branch lengths of
76                ``containing_tree`` will be adjusted to fit the contained tree
77                as they are added. Otherwise, the containing tree edge lengths
78                will not be changed.
79
80            ``collapse_empty_edges``
81                If |True| [default], after edge lengths are adjusted,
82                zero-length branches will be collapsed.
83
84            ``ultrametricity_precision``
85                If |False| [default], then trees will not be checked for
86                ultrametricity. Otherwise this is the threshold within which
87                all node to tip distances for sister nodes must be equal.
88
89            ``ignore_root_deep_coalescences``
90                If |True| [default], then deep coalescences in the root will
91                not be counted.
92
93        Other Keyword Arguments: Will be passed to Tree().
94
95    """
96        if "taxon_namespace" not in kwargs:
97            kwargs["taxon_namespace"] = containing_tree.taxon_namespace
98        dendropy.Tree.__init__(self,
99                containing_tree,
100                taxon_namespace=containing_tree.taxon_namespace)
101        self.original_tree = containing_tree
102        for edge in self.postorder_edge_iter():
103            edge.head_contained_edges = {}
104            edge.tail_contained_edges = {}
105            edge.containing_taxa = set()
106            edge.contained_taxa = set()
107        self._contained_taxon_namespace = contained_taxon_namespace
108        self._contained_to_containing_taxon_map = None
109        self._contained_trees = None
110        self._set_contained_to_containing_taxon_map(contained_to_containing_taxon_map)
111        self.fit_containing_edge_lengths = fit_containing_edge_lengths
112        self.collapse_empty_edges = collapse_empty_edges
113        self.ultrametricity_precision = ultrametricity_precision
114        self.ignore_root_deep_coalescences = ignore_root_deep_coalescences
115        if contained_trees:
116            self._set_contained_trees(contained_trees)
117        if self.contained_trees:
118            self.rebuild(rebuild_taxa=False)
119
120    def _set_contained_taxon_namespace(self, taxon_namespace):
121        self._contained_taxon_namespace = taxon_namespace
122
123    def _get_contained_taxon_namespace(self):
124        if self._contained_taxon_namespace is None:
125            self._contained_taxon_namespace = dendropy.TaxonNamespace()
126        return self._contained_taxon_namespace
127
128    contained_taxon_namespace = property(_get_contained_taxon_namespace)
129
130    def _set_contained_to_containing_taxon_map(self, contained_to_containing_taxon_map):
131        """
132        Sets mapping of |Taxon| objects of the genes/parasite/etc. to that of
133        the population/species/host/etc.
134        Creates mapping (e.g., species to genes) and decorates edges of self
135        with sets of both containing |Taxon| objects and the contained
136        |Taxon| objects that map to them.
137        """
138        if isinstance(contained_to_containing_taxon_map, dendropy.TaxonNamespaceMapping):
139            if self._contained_taxon_namespace is not contained_to_containing_taxon_map.domain_taxon_namespace:
140                raise ValueError("Domain TaxonNamespace of TaxonNamespaceMapping ('domain_taxon_namespace') not the same as 'contained_taxon_namespace' TaxonNamespace")
141            self._contained_to_containing_taxon_map = contained_to_containing_taxon_map
142        else:
143            self._contained_to_containing_taxon_map = dendropy.TaxonNamespaceMapping(
144                    mapping_dict=contained_to_containing_taxon_map,
145                    domain_taxon_namespace=self.contained_taxon_namespace,
146                    range_taxon_namespace=self.taxon_namespace)
147        self.build_edge_taxa_sets()
148
149    def _get_contained_to_containing_taxon_map(self):
150        return self._contained_to_containing_taxon_map
151
152    contained_to_containing_taxon_map = property(_get_contained_to_containing_taxon_map)
153
154    def _set_contained_trees(self, trees):
155        if hasattr(trees, 'taxon_namespace'):
156            if self._contained_taxon_namespace is None:
157                self._contained_taxon_namespace = trees.taxon_namespace
158            elif self._contained_taxon_namespace is not trees.taxon_namespace:
159                raise ValueError("'contained_taxon_namespace' of ContainingTree is not the same TaxonNamespace object of 'contained_trees'")
160        self._contained_trees = dendropy.TreeList(trees, taxon_namespace=self._contained_taxon_namespace)
161        if self._contained_taxon_namespace is None:
162            self._contained_taxon_namespace = self._contained_trees.taxon_namespace
163
164    def _get_contained_trees(self):
165        if self._contained_trees is None:
166            self._contained_trees = dendropy.TreeList(taxon_namespace=self._contained_taxon_namespace)
167        return self._contained_trees
168
169    contained_trees = property(_get_contained_trees)
170
171    def _get_containing_to_contained_taxa_map(self):
172        return self._contained_to_containing_taxon_map.reverse
173
174    containing_to_contained_taxa_map = property(_get_containing_to_contained_taxa_map)
175
176    def clear(self):
177        """
178        Clears all contained trees and mapped edges.
179        """
180        self.contained_trees = dendropy.TreeList(taxon_namespace=self._contained_to_containing_taxon_map.domain_taxa)
181        self.clear_contained_edges()
182
183    def clear_contained_edges(self):
184        """
185        Clears all contained mapped edges.
186        """
187        for edge in self.postorder_edge_iter():
188            edge.head_contained_edges = {}
189            edge.tail_contained_edges = {}
190
191    def fit_edge_lengths(self, contained_trees):
192        """
193        Recalculate node ages / edge lengths of containing tree to accomodate
194        contained trees.
195        """
196
197        # set the ages
198        for node in self.postorder_node_iter():
199            if node.is_internal():
200                disjunct_leaf_set_list_split_bitmasks = []
201                for i in node.child_nodes():
202                    disjunct_leaf_set_list_split_bitmasks.append(self.taxon_namespace.taxa_bitmask(taxa=i.edge.containing_taxa))
203                min_age = float('inf')
204                for et in contained_trees:
205                    min_age = self._find_youngest_intergroup_age(et, disjunct_leaf_set_list_split_bitmasks, min_age)
206                node.age = max( [min_age] + [cn.age for cn in node.child_nodes()] )
207            else:
208                node.age = 0
209
210        # set the corresponding edge lengths
211        self.set_edge_lengths_from_node_ages()
212
213        # collapse 0-length branches
214        if self.collapse_empty_edges:
215           self.collapse_unweighted_edges()
216
217    def rebuild(self, rebuild_taxa=True):
218        """
219        Recalculate edge taxa sets, node ages / edge lengths of containing
220        tree, and embed edges of contained trees.
221        """
222        if rebuild_taxa:
223            self.build_edge_taxa_sets()
224        if self.fit_containing_edge_lengths:
225            self.fit_edge_lengths(self.contained_trees)
226        self.clear_contained_edges()
227        for et in self.contained_trees:
228            self.embed_tree(et)
229
230    def embed_tree(self, contained_tree):
231        """
232        Map edges of contained tree into containing tree (i.e., self).
233        """
234        if self.seed_node.age is None:
235            self.calc_node_ages(ultrametricity_precision=self.ultrametricity_precision)
236        if contained_tree not in self.contained_trees:
237            self.contained_trees.append(contained_tree)
238        if self.fit_containing_edge_lengths:
239            self.fit_edge_lengths(self.contained_trees)
240        if contained_tree.seed_node.age is None:
241            contained_tree.calc_node_ages(ultrametricity_precision=self.ultrametricity_precision)
242        contained_leaves = contained_tree.leaf_nodes()
243        taxon_to_contained = {}
244        for nd in contained_leaves:
245            containing_taxon = self.contained_to_containing_taxon_map[nd.taxon]
246            x = taxon_to_contained.setdefault(containing_taxon, set())
247            x.add(nd.edge)
248        for containing_edge in self.postorder_edge_iter():
249            if containing_edge.is_terminal():
250                containing_edge.head_contained_edges[contained_tree] = taxon_to_contained[containing_edge.head_node.taxon]
251            else:
252                containing_edge.head_contained_edges[contained_tree] = set()
253                for nd in containing_edge.head_node.child_nodes():
254                    containing_edge.head_contained_edges[contained_tree].update(nd.edge.tail_contained_edges[contained_tree])
255
256            if containing_edge.tail_node is None:
257                if containing_edge.length is not None:
258                    target_age =  containing_edge.head_node.age + containing_edge.length
259                else:
260                    # assume all coalesce?
261                    containing_edge.tail_contained_edges[contained_tree] = set([contained_tree.seed_node.edge])
262                    continue
263            else:
264                target_age = containing_edge.tail_node.age
265
266            containing_edge.tail_contained_edges[contained_tree] = set()
267            for contained_edge in containing_edge.head_contained_edges[contained_tree]:
268                if contained_edge.tail_node is not None:
269                    remaining = target_age - contained_edge.tail_node.age
270                elif contained_edge.length is not None:
271                    remaining = target_age - (contained_edge.head_node.age + contained_edge.length)
272                else:
273                    continue
274                while remaining > 0:
275                    if contained_edge.tail_node is not None:
276                        contained_edge = contained_edge.tail_node.edge
277                    else:
278                        if contained_edge.length is not None and (remaining - contained_edge.length) <= 0:
279                            contained_edge = None
280                            remaining = 0
281                            break
282                        else:
283                            remaining = 0
284                            break
285                    if contained_edge and remaining > 0:
286                        remaining -= contained_edge.length
287                if contained_edge is not None:
288                    containing_edge.tail_contained_edges[contained_tree].add(contained_edge)
289
290    def build_edge_taxa_sets(self):
291        """
292        Rebuilds sets of containing and corresponding contained taxa at each
293        edge.
294        """
295        for edge in self.postorder_edge_iter():
296            if edge.is_terminal():
297                edge.containing_taxa = set([edge.head_node.taxon])
298            else:
299                edge.containing_taxa = set()
300                for i in edge.head_node.child_nodes():
301                    edge.containing_taxa.update(i.edge.containing_taxa)
302            edge.contained_taxa = set()
303            for t in edge.containing_taxa:
304                edge.contained_taxa.update(self.containing_to_contained_taxa_map[t])
305
306    def num_deep_coalescences(self):
307        """
308        Returns total number of deep coalescences of the contained trees.
309        """
310        return sum(self.deep_coalescences().values())
311
312    def deep_coalescences(self):
313        """
314        Returns dictionary where the contained trees are keys, and the number of
315        deep coalescences corresponding to the tree are values.
316        """
317        dc = {}
318        for tree in self.contained_trees:
319            for edge in self.postorder_edge_iter():
320                if edge.tail_node is None and self.ignore_root_deep_coalescences:
321                    continue
322                try:
323                    dc[tree] += len(edge.tail_contained_edges[tree]) - 1
324                except KeyError:
325                    dc[tree] = len(edge.tail_contained_edges[tree]) - 1
326        return dc
327
328    def embed_contained_kingman(self,
329            edge_pop_size_attr='pop_size',
330            default_pop_size=1,
331            label=None,
332            rng=None,
333            use_expected_tmrca=False):
334        """
335        Simulates, *embeds*, and returns a "censored" (Kingman) neutral coalescence tree
336        conditional on self.
337
338            ``rng``
339                Random number generator to use. If |None|, the default will
340                be used.
341
342            ``edge_pop_size_attr``
343                Name of attribute of self's edges that specify the population
344                size. If this attribute does not exist, then the population
345                size is taken to be 1.
346
347        Note that all edge-associated taxon sets must be up-to-date (otherwise,
348        ``build_edge_taxa_sets()`` should be called).
349        """
350        et = self.simulate_contained_kingman(
351                edge_pop_size_attr=edge_pop_size_attr,
352                default_pop_size=default_pop_size,
353                label=label,
354                rng=rng,
355                use_expected_tmrca=use_expected_tmrca)
356        self.embed_tree(et)
357        return et
358
359    def simulate_contained_kingman(self,
360            edge_pop_size_attr='pop_size',
361            default_pop_size=1,
362            label=None,
363            rng=None,
364            use_expected_tmrca=False):
365        """
366        Simulates and returns a "censored" (Kingman) neutral coalescence tree
367        conditional on self.
368
369            ``rng``
370                Random number generator to use. If |None|, the default will
371                be used.
372
373            ``edge_pop_size_attr``
374                Name of attribute of self's edges that specify the population
375                size. If this attribute does not exist, then the population
376                size is taken to be 1.
377
378        Note that all edge-associated taxon sets must be up-to-date (otherwise,
379        ``build_edge_taxa_sets()`` should be called), and that the tree
380        is *not* added to the set of contained trees. For the latter, call
381        ``embed_contained_kingman``.
382        """
383
384        # Dictionary that maps nodes of containing tree to list of
385        # corresponding nodes on gene tree, initially populated with leaf
386        # nodes.
387        contained_nodes = {}
388        for nd in self.leaf_node_iter():
389            contained_nodes[nd] = []
390            for gt in nd.edge.contained_taxa:
391                gn = dendropy.Node(taxon=gt)
392                contained_nodes[nd].append(gn)
393
394        # Generate the tree structure
395        for edge in self.postorder_edge_iter():
396            if edge.head_node.parent_node is None:
397                # root: run unconstrained coalescence until just one gene node
398                # remaining
399                if hasattr(edge, edge_pop_size_attr):
400                    pop_size = getattr(edge, edge_pop_size_attr)
401                else:
402                    pop_size = default_pop_size
403                if len(contained_nodes[edge.head_node]) > 1:
404                    final = coalescent.coalesce_nodes(nodes=contained_nodes[edge.head_node],
405                            pop_size=pop_size,
406                            period=None,
407                            rng=rng,
408                            use_expected_tmrca=use_expected_tmrca)
409                else:
410                    final = contained_nodes[edge.head_node]
411            else:
412                # run until next coalescence event, as determined by this edge
413                # size.
414                if hasattr(edge, edge_pop_size_attr):
415                    pop_size = getattr(edge, edge_pop_size_attr)
416                else:
417                    pop_size = default_pop_size
418                remaining = coalescent.coalesce_nodes(nodes=contained_nodes[edge.head_node],
419                        pop_size=pop_size,
420                        period=edge.length,
421                        rng=rng,
422                        use_expected_tmrca=use_expected_tmrca)
423                try:
424                    contained_nodes[edge.tail_node].extend(remaining)
425                except KeyError:
426                    contained_nodes[edge.tail_node] = remaining
427
428        # Create and return the full tree
429        contained_tree = dendropy.Tree(taxon_namespace=self.contained_taxon_namespace, label=label)
430        contained_tree.seed_node = final[0]
431        contained_tree.is_rooted = True
432        return contained_tree
433
434    def _find_youngest_intergroup_age(self, contained_tree, disjunct_leaf_set_list_split_bitmasks, starting_min_age=None):
435        """
436        Find the age of the youngest MRCA of disjunct leaf sets.
437        """
438        if starting_min_age is None:
439            starting_min_age = float('inf')
440        if contained_tree.seed_node.age is None:
441            contained_tree.calc_node_ages(ultrametricity_precision=self.ultrametricity_precision)
442        for nd in contained_tree.ageorder_node_iter(include_leaves=False):
443            if nd.age > starting_min_age:
444                break
445            prev_intersections = False
446            for bm in disjunct_leaf_set_list_split_bitmasks:
447                if bm & nd.edge.split_bitmask:
448                    if prev_intersections:
449                        return nd.age
450                    prev_intersections = True
451        return starting_min_age
452
453    def write_as_mesquite(self, out, **kwargs):
454        """
455        For debugging purposes, write out a Mesquite-format file.
456        """
457        from dendropy.dataio import nexuswriter
458        nw = nexuswriter.NexusWriter(**kwargs)
459        nw.is_write_block_titles = True
460        out.write("#NEXUS\n\n")
461        nw._write_taxa_block(out, self.taxon_namespace)
462        out.write('\n')
463        nw._write_taxa_block(out, self.contained_trees.taxon_namespace)
464        if self.contained_trees.taxon_namespace.label:
465            domain_title = self.contained_trees.taxon_namespace.label
466        else:
467            domain_title = self.contained_trees.taxon_namespace.oid
468        contained_taxon_namespace = self.contained_trees.taxon_namespace
469        contained_label = self.contained_trees.label
470        out.write('\n')
471        self._contained_to_containing_taxon_map.write_mesquite_association_block(out)
472        out.write('\n')
473        nw._write_trees_block(out, dendropy.TreeList([self], taxon_namespace=self.taxon_namespace))
474        out.write('\n')
475        nw._write_trees_block(out, dendropy.TreeList(self.contained_trees, taxon_namespace=contained_taxon_namespace, label=contained_label))
476        out.write('\n')
477
478def reconciliation_discordance(gene_tree, species_tree):
479    """
480    Given two trees (with splits encoded), this returns the number of gene
481    duplications implied by the gene tree reconciled on the species tree, based
482    on the algorithm described here:
483
484        Goodman, M. J. Czelnusiniak, G. W. Moore, A. E. Romero-Herrera, and
485        G. Matsuda. 1979. Fitting the gene lineage into its species lineage,
486        a parsimony strategy illustrated by cladograms constructed from globin
487        sequences. Syst. Zool. 19: 99-113.
488
489        Maddison, W. P. 1997. Gene trees in species trees. Syst. Biol. 46:
490        523-536.
491
492    This function requires that the gene tree and species tree *have the same
493    leaf set*. Note that for correct results,
494
495        (a) trees must be rooted (i.e., is_rooted = True)
496        (b) split masks must have been added as rooted (i.e., when
497            encode_splits was called, is_rooted must have been set to True)
498
499    """
500    taxa_mask = species_tree.taxon_namespace.all_taxa_bitmask()
501    species_node_gene_nodes = {}
502    gene_node_species_nodes = {}
503    for gnd in gene_tree.postorder_node_iter():
504        gn_children = gnd.child_nodes()
505        if len(gn_children) > 0:
506            ssplit = 0
507            for gn_child in gn_children:
508                ssplit = ssplit | gene_node_species_nodes[gn_child].edge.leafset_bitmask
509            sanc = species_tree.mrca(start_node=species_tree.seed_node, leafset_bitmask=ssplit)
510            gene_node_species_nodes[gnd] = sanc
511            if sanc not in species_node_gene_nodes:
512                species_node_gene_nodes[sanc] = []
513            species_node_gene_nodes[sanc].append(gnd)
514        else:
515            gene_node_species_nodes[gnd] = species_tree.find_node(lambda x : x.taxon == gnd.taxon)
516    contained_gene_lineages = {}
517    for snd in species_tree.postorder_node_iter():
518        if snd in species_node_gene_nodes:
519            for gnd in species_node_gene_nodes[snd]:
520                for gnd_child in gnd.child_nodes():
521                    sanc = gene_node_species_nodes[gnd_child]
522                    p = sanc
523                    while p is not None and p != snd:
524                        if p.edge not in contained_gene_lineages:
525                            contained_gene_lineages[p.edge] = 0
526                        contained_gene_lineages[p.edge] += 1
527                        p = p.parent_node
528
529    dc = 0
530    for v in contained_gene_lineages.values():
531        dc += v - 1
532    return dc
533
534def monophyletic_partition_discordance(tree, taxon_namespace_partition):
535    """
536    Returns the number of deep coalescences on tree ``tree`` that would result
537    if the taxa in ``tax_sets`` formed K mutually-exclusive monophyletic groups,
538    where K = len(tax_sets)
539    ``taxon_namespace_partition`` == TaxonNamespacePartition
540    """
541
542    tax_sets = taxon_namespace_partition.subsets()
543
544    # from dendropy.model import parsimony
545    # taxon_state_sets_map = {}
546    # assert tree.taxon_namespace is taxon_namespace_partition.taxon_namespace
547    # for taxon in tree.taxon_namespace:
548    #     taxon_state_sets_map[taxon] = [0 for i in range(len(tax_sets))]
549    # for idx, ts in enumerate(tax_sets):
550    #     for taxon in ts:
551    #         taxon_state_sets_map[taxon][idx] = 1
552    # for taxon in tree.taxon_namespace:
553    #     taxon_state_sets_map[taxon] = [set([i]) for i in taxon_state_sets_map[taxon]]
554    # return parsimony.fitch_down_pass(
555    #         postorder_nodes=tree.postorder_node_iter(),
556    #         taxon_state_sets_map=taxon_state_sets_map
557    #         )
558
559    dc_tree = dendropy.Tree()
560    dc_tree.taxon_namespace = dendropy.TaxonNamespace()
561    for t in range(len(tax_sets)):
562        dc_tree.taxon_namespace.add_taxon(dendropy.Taxon(label=str(t)))
563    def _get_dc_taxon(nd):
564        for idx, tax_set in enumerate(tax_sets):
565            if nd.taxon in tax_set:
566                return dc_tree.taxon_namespace[idx]
567        assert "taxon not found in partition: '%s'" % nd.taxon.label
568    src_dc_map = {}
569    for snd in tree.postorder_node_iter():
570        nnd = dendropy.Node()
571        src_dc_map[snd] = nnd
572        children = snd.child_nodes()
573        if len(children) == 0:
574            nnd.taxon = _get_dc_taxon(snd)
575        else:
576            taxa_set = []
577            for cnd in children:
578                dc_node = src_dc_map[cnd]
579                if len(dc_node.child_nodes()) > 1:
580                    nnd.add_child(dc_node)
581                else:
582                    ctax = dc_node.taxon
583                    if ctax is not None and ctax not in taxa_set:
584                        taxa_set.append(ctax)
585                    del src_dc_map[cnd]
586            if len(taxa_set) > 1:
587                for t in taxa_set:
588                    cnd = dendropy.Node()
589                    cnd.taxon = t
590                    nnd.add_child(cnd)
591            else:
592                if len(nnd.child_nodes()) == 0:
593                    nnd.taxon = taxa_set[0]
594                elif len(taxa_set) == 1:
595                    cnd = dendropy.Node()
596                    cnd.taxon = taxa_set[0]
597                    nnd.add_child(cnd)
598    dc_tree.seed_node = nnd
599    return len(dc_tree.leaf_nodes()) - len(tax_sets)
600
601