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agormp / sumt

Computes consensus trees and other phylogenetic tree summaries
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sumt

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The command-line program sumt computes consensus trees and other tree-summary statistics for sets of phylogenetic trees. The input trees can be in one or more input files, and will typically be from a Bayesian MCMC analysis (BEAST or MrBayes for instance) or from a bootstrap procedure.

sumt can compute four different kinds of main tree summaries:

Branch labels on these trees indicate clade support.

sumt also produces a summary of observed bipartitions along with branch length means and variances and, optionally, a list of tree topologies and how frequently they were observed. The name is taken from the sumt command in MrBayes, whose functionality it was originally meant to resemble. Clade support values and topology frequencies can be interpreted as posterior probabilities if the input trees are from a Bayesian MCMC analysis.

Availability

The sumt source code is available on GitHub: https://github.com/agormp/sumt. The executable can be installed from PyPI: https://pypi.org/project/sumt/

Installation

python3 -m pip install sumt

Upgrading to latest version:

python3 -m pip install --upgrade sumt

Citation

To cite sumt: use the link in the right sidebar under About --> Cite this repository.

Dependencies

sumt relies on the phylotreelib library for phylogeny-related matters, and on psutil for (optionally) monitoring memory usage. These are automatically included when using pip to install.

Overview

Usage

usage: sumt [-h] [--version] [--con | --all | --mcc | --mbc]
            [--noblen | --biplen | --meandepth | --cadepth]
            [--rootmid | --rootminvar | -r TAXON [TAXON ...] | --rootfile FILE |
            --rootmaxfreq] [-b NUM] [-t NUM] [-s] [-f NUM] [-n] [-v] [-q] [--basename NAME]
            [--autow] [--informat FORMAT] [-i FILE | -w WEIGHT FILE]

Computes summary tree and statistics from set of phylogenetic trees

options:
  -h, --help            show this help message and exit
  --version             show the program's version number and exit

Type of summary tree (pick one option):
  --con                 majority rule consensus tree
  --all                 majority rule consensus tree with all compatible bipartitions added
  --mcc                 Maximum Clade Credibility (MCC) tree. The MCC tree is determined by
                        inspecting tree samples and selecting the tree that has the highest
                        product of clade frequencies (= highest sum of log of clade
                        frequencies). The MCC tree is therefore a tree that has been
                        observed in the pool of tree samples, differing from the consensus
                        tree which typically does not match any individual sample. NOTE 1:
                        only meaningful if input trees are estimated using clock model.
                        NOTE 2: by default, the MCC tree uses the rooting of the specific
                        tree sample. This will often (but not always) correspond to the
                        bipartition where the root is most commonly found in the input
                        trees.
  --mbc                 Maximum Bipartition Credibility (MBC) tree. The MBC tree is similar
                        to the MCC tree but counting bipartitions instead of clades, i.e.
                        ignoring rooting (two input trees can have the same set of
                        bipartitions, but be rooted in different locations).

Estimation of branch lengths (pick one option):
  --noblen              Do not set branch lengths (only the topology and branch- or clade-
                        support of the summary tree are estimated).
  --biplen              Set branch lengths in summary tree based on average for
                        corresponding leaf bipartitions:each branch in tree corresponds to
                        a bipartition of the leaves into two groups. Branch lenghts are set
                        to the mean of the length of thecorresponding bipartition across
                        all input trees.
  --meandepth           set node depth for each clade to mean node depth observed for that
                        clade among input trees (and branch lengths are then based on these
                        depths). Warning: option is intended for input trees estimated
                        using a clock model. It requires that all clades in the summary
                        tree have been observed in the input trees, and may fail for some
                        rootings.NOTE: mean is computed across trees where the specific,
                        monophyletic clade is present, and may therefore be based on very
                        few (down to one) values. NOTE 2: may result in negative branch
                        lengths.
  --cadepth             'Common Ancestor depth'. Same as option '--height ca' in
                        treeannotator. Uses all trees in input set when determining node-
                        depths. For a given clade: (1) Find the most recent common ancestor
                        of the leaves in that clade in each of the input trees. (2) Compute
                        node-depth of clade as the mean of the depths of these MRCAs. This
                        is different from --meandepth where only trees with that exact
                        clade are included when computing the mean. Warning: option is
                        intended for input trees estimated using a clock model. It requires
                        that all clades in the summary tree have been observed in the input
                        trees, and may fail for some rootings.

Rooting of summary tree:
  --rootmid             perform midpoint rooting of summary tree
  --rootminvar          perform minimum variance rooting of summary tree
  -r TAXON [TAXON ...]  root summary tree on specified outgroup taxon/taxa
  --rootfile FILE       root summary tree on outgroup taxa listed in file (one name per
                        line)
  --rootmaxfreq         root summary tree on bipartition where root is located most
                        frequently in input trees. NOTE: only meaningful if input trees are
                        estimated using clock model

Bayesian phylogeny options:
  -b NUM [NUM ...]      burnin: fraction of trees to discard [0 - 1; default: 0.0].
                        Either one value (used on all input files), or one value per
                        input file.
  -t NUM                compute tree probabilities, report NUM percent credible interval [0
                        - 1]
  -s                    compute average standard deviation of split frequencies (ASDSF)
  -f NUM                Minimum frequency for including bipartitions in report and in
                        computation of ASDSF [default: 0.1]

Output to terminal and files:
  -n                    no warning when overwriting files
  -v                    verbose: show full traceback in the event of failed python
                        execution
  -q                    quiet: don't print progress indication to terminal window. NOTE:
                        also turns on the -n option
  --basename NAME       base name of output files (default: derived from input file)

Other options:
  --autow               automatically assign file weights based on tree counts, so all
                        files have equal impact (default is for all trees, not files, to be
                        equally important)
  --informat FORMAT     format of input files: nexus, newick [default: nexus]

Input tree files:
  -i FILE               input FILE(s) containing phylogenetic trees (repeat -i FILE option
                        for each input file)
  -w WEIGHT FILE        input FILEs with specified weights (repeat -w WEIGHT FILE option
                        for each input file)

Usage examples

Example 1:

Majority rule consensus tree, bipartition summary, topology summary, computation of average standard deviation of split frequencies, midpoint rooting

The command below causes sumt to do the following:

sumt --con -b 0.25 -t 0.99 -f 0.1 --rootmid --biplen -i primates.run1.t -i primates.run2.t

Screen output

This is printed to screen during run:

   Counting trees in file tests/primates.run1.t                             2,001
   Counting trees in file tests/primates.run2.t                             2,001

   Analyzing file: tests/primates.run1.t (Weight: 1.000)
   Discarded 500 of 2,001 trees (burnin fraction=0.25)

   Processing trees:

   0      10      20      30      40      50      60      70      80      90     100
   v-------v-------v-------v-------v-------v-------v-------v-------v-------v-------v
   *********************************************************************************

   Analyzing file: tests/primates.run2.t (Weight: 1.000)
   Discarded 500 of 2,001 trees (burnin fraction=0.25)

   Processing trees:

   0      10      20      30      40      50      60      70      80      90     100
   v-------v-------v-------v-------v-------v-------v-------v-------v-------v-------v
   *********************************************************************************

   Computing consensus tree...done.
   Consensus tree written to primates.con
   Bipartition list written to primates.parts
   Tree probabilities written to primates.trprobs

   Number of leaves on input trees:       5
   Different topologies seen:             3
   Different bipartitions seen:           4 (theoretical maximum: 6)
   Bipartitions in Consensus tree:        2 (theoretical maximum: 2)
                                            (tree is fully resolved - no polytomies)

   Consensus tree has been midpoint-rooted

   Branch lengths set based on mean branch lengths for corresponding bipartitions

   Log bipartition credibility:  -0.028723

   Done. 3,002 trees analyzed.
   Time spent: 0:00:00 (h:m:s)
   Max memory used: 31.91 MB.

Bipartition overview

Below are the contents of the file primates.parts, which lists information about bipartitions observed in input trees. A bipartition - or split - is a division of leaf-names into two groups: those on one side of an internal branch, and those on the other side. Two trees with different topologies can have the same bipartition, and that internal branch is then said to have been observed in both trees. sumt keeps track of bipartition frequencies, as well as means and variances of the lengths of the corresponding branches. For branches included on the summary tree, the clade support value is the same as the value in the column PROB (i.e., the frequency of the bipartion among the input trees).

Bipartitions are indicated using the "asterisk and dots" notation also used by e.g. MrBayes: Columns correspond to taxa (with column 1 = taxon 1). All taxa with "*" (or ".") are in the same half of the bipartition. The ID column contains either a leaf name or a numerical branchID that corresponds to branch labels given in the second tree in the consensus tree file (in this case there are 5 leaves, and therefore only two internal branches). Branch IDs are numbered consecutively in order of bipartition frequency (so the branch with ID=7 has the 7th highest observed bipartition frequency).

List of bipartitions:

PART = Description of partition in .* format
PROB = Posterior probability of the partition
BLEN = Mean branch length
VAR  = Branch length variance
SEM  = Standard error of the mean for branch length
ID   = Leaf name or internal branch label, for those bipartitions that are included in consensus tree

PART    PROB      BLEN       VAR          SEM          ID
*....   1.000000  0.07561    (0.0003703)  (0.0003512)  Chimpanzee
.*...   1.000000  0.3551     (0.01894  )  (0.002512 )  Gibbon
..*..   1.000000  0.0728     (0.0005512)  (0.0004285)  Gorilla
...*.   1.000000  0.05689    (0.0002746)  (0.0003025)  Human
....*   1.000000  0.2793     (0.008997 )  (0.001731 )  Orangutan
.*..*   1.000000  0.1464     (0.003637 )  (0.001101 )  6
*..*.   0.971686  0.03674    (0.0004015)  (0.000371 )  7

Tree probabilities

This is the content of the file primates.trprobs. In this case there were only 5 leaves corresponding to a total of 15 possible trees, of which 3 were seen in the MCMC samples. Note: For data sets with more than about 15-20 taxa, each sampled tree will typically be unique and all topologies therefore have the same probability, meaning the credible set is not very useful. (Bipartitions or clades on those trees will, however, not be unique, and clade probabilities carry useful information).

#NEXUS

[This file contains the 99% most probable trees found during the
MCMC search, sorted by posterior probability (the 99% HPD interval).
Lower case 'p' indicates the posterior probability of a tree.
Upper case 'P' indicates the cumulative posterior probability.]

begin trees;
    translate
        1     Chimpanzee,
        2     Gibbon,
        3     Gorilla,
        4     Human,
        5     Orangutan
    ;
    tree tree_1 [p = 0.971686] [P = 0.971686] = ((3,(5,2)),1,4);
    tree tree_2 [p = 0.014990] [P = 0.986676] = ((5,2),(3,1),4);
    tree tree_3 [p = 0.013324] [P = 1.000000] = (((5,2),1),3,4);
end;

Consensus tree

This is the content of the file primates.con. The difference between the two trees is the information given as branch labels:

#NEXUS

begin trees;
   [In this tree branch labels indicate the posterior probability of the bipartition corresponding to the branch.]
   tree prob = ((Orangutan:0.279279,(Gorilla:0.0728019,(Chimpanzee:0.0756054,Human:0.0568895)0.972:0.0367431)1.000:0.146428):0.0758066,Gibbon:0.355086);

   [In this tree branch labels indicate the bipartition ID listed in the file primates.parts.
    These branch labels can be used for interpreting the table of branch lenght info in that file]
   tree partID = ((Orangutan:0.279279,(Gorilla:0.0728019,(Chimpanzee:0.0756054,Human:0.0568895)7:0.0367431)6:0.146428):0.0758066,Gibbon:0.355086);
end;

Example 2:

Maximum bipartition credibility tree, topology summary, setting basename of output files

The command below causes sumt to do the following:

sumt --mbc -b 0.1 -t 0.75 -n --basename /Users/bob/hiv --biplen -i gp120.trees

Example 3:

Consensus tree with all compatible bipartitions, outgroup rooting

The command below causes sumt to do the following:

sumt --all -b 0.1 -t 0.95 -n -r macaque olive_baboon yellow_baboon ---biplen i mhc_align.run1.t

Example 4:

Maximum clade credibility tree with "common ancestor" node depths, separate burnins

The command below causes sumt to do the following:

sumt --mcc -b 0.25 0.4 --cadepth -ns --basename beast_summary -i beastrun1.trees -i beastrun2.trees

Screen output

This is printed to screen during run:

   Counting trees in file tests/beastrun1.trees                             2,001
   Counting trees in file tests/beastrun2.trees                             2,001

   Analyzing file: tests/beastrun1.trees (Weight: 1.000)
   Discarded 500 of 2,001 trees (burnin fraction=0.25)

   Processing trees:

   0      10      20      30      40      50      60      70      80      90     100
   v-------v-------v-------v-------v-------v-------v-------v-------v-------v-------v
   *********************************************************************************

   Analyzing file: tests/beastrun2.trees (Weight: 1.000)
   Discarded 500 of 2,001 trees (burnin fraction=0.25)

   Processing trees:

   0      10      20      30      40      50      60      70      80      90     100
   v-------v-------v-------v-------v-------v-------v-------v-------v-------v-------v
   *********************************************************************************

   Finding Maximum Clade Credibility tree...done.
   Computing common ancestor depths...done.
   Maximum clade credibility tree written to beast_summary.mcc

   Number of leaves on input trees:     508
   Different clades seen:           193,339 (theoretical maximum: 1,522,014)
   Bipartitions in MCC tree:            505 (theoretical maximum: 505)
                                            (tree is fully resolved - no polytomies)

   MCC tree rooted at original root of tree sample having highest clade credibility
   Root credibility (frequency of root bipartition in input trees): 86.3%

   Branch lengths set based on common ancestor depths in input trees

   Highest log clade credibility:  -1253.6
   Average standard deviation of split frequencies: 0.022985

   Done. 3,002 trees analyzed.
   Time spent: 0:00:31 (h:m:s)
   Max memory used: 2.15 GB.

Example 5:

Maximum clade credibility tree with mean node depths

The command below causes sumt to do the following:

sumt --mcc -b 0.25 --meandepth -ns --basename beast_summary -i beastrun1.trees -i beastrun2.trees

Example 6:

Maximum bipartition credibility tree with common ancestor node depths, rooted at most frequent position

The command below causes sumt to do the following:

sumt --mbc -b 0.25 --cadepth --rootmaxfreq -ns --basename beast_summary -i beastrun1.trees -i beastrun2.trees

Screen output

This is printed to screen during run:

   Counting trees in file tests/beastrun1.trees                             2,001
   Counting trees in file tests/beastrun2.trees                             2,001

   Analyzing file: tests/beastrun1.trees (Weight: 1.000)
   Discarded 500 of 2,001 trees (burnin fraction=0.25)

   Processing trees:

   0      10      20      30      40      50      60      70      80      90     100
   v-------v-------v-------v-------v-------v-------v-------v-------v-------v-------v
   *********************************************************************************

   Analyzing file: tests/beastrun2.trees (Weight: 1.000)
   Discarded 500 of 2,001 trees (burnin fraction=0.25)

   Processing trees:

   0      10      20      30      40      50      60      70      80      90     100
   v-------v-------v-------v-------v-------v-------v-------v-------v-------v-------v
   *********************************************************************************

   Finding Maximum Bipartition Credibility tree...done.
   Computing common ancestor depths...done.
   Maximum bipartition credibility tree written to beast_summary.mbc

   Number of leaves on input trees:     508
   Different bipartitions seen:     193,333 (theoretical maximum: 1,516,010)
   Bipartitions in MBC tree:            505 (theoretical maximum: 505)
                                            (tree is fully resolved - no polytomies)

   MBC tree has been rooted at location most frequently observed in input trees
   Root credibility (frequency of root bipartition in input trees): 86.3%

   Branch lengths set based on common ancestor depths in input trees

   Highest log bipartition credibility:  -1253.45
   Average standard deviation of split frequencies: 0.023034

   Done. 3,002 trees analyzed.
   Time spent: 0:00:44 (h:m:s)
   Max memory used: 2.43 GB.