TreeLength: Calculate the parsimony score of a tree given a dataset

In TreeSearch: Phylogenetic Analysis with Discrete Character Data

Calculate the parsimony score of a tree given a dataset

Description

TreeLength() uses the Morphy library \insertCiteBrazeau2017TreeSearch to calculate a parsimony score for a tree, handling inapplicable data according to the algorithm of \insertCiteBrazeau2019;textualTreeSearch. Trees may be scored using equal weights, implied weights \insertCiteGoloboff1993TreeSearch, or profile parsimony \insertCiteFaith2001TreeSearch.

Usage

IWScore(tree, dataset, concavity = 10L, ...)

TreeLength(tree, dataset, concavity = Inf)

## S3 method for class 'phylo'
TreeLength(tree, dataset, concavity = Inf)

## S3 method for class 'numeric'
TreeLength(tree, dataset, concavity = Inf)

## S3 method for class 'list'
TreeLength(tree, dataset, concavity = Inf)

## S3 method for class 'multiPhylo'
TreeLength(tree, dataset, concavity = Inf)

Fitch(tree, dataset)

Arguments

tree	A tree of class phylo, a list thereof (optionally of class multiPhylo), or an integer – in which case tree random trees will be uniformly sampled.
dataset	A phylogenetic data matrix of phangorn class phyDat, whose names correspond to the labels of any accompanying tree. Perhaps load into R using ReadAsPhyDat. Additive (ordered) characters can be handled using Decompose.
concavity	Determines the degree to which extra steps beyond the first are penalized. Specify a numeric value to use implied weighting \insertCiteGoloboff1993TreeSearch; concavity specifies k in k / e + k. A value of 10 is recommended; TNT sets a default of 3, but this is too low in some circumstances \insertCiteGoloboff2018,Smith2019TreeSearch. Better still explore the sensitivity of results under a range of concavity values, e.g. k = 2 ^ (1:7). Specify Inf to weight each additional step equally, (which underperforms step weighting approaches \insertCiteGoloboff2008,Goloboff2018,Goloboff2019,Smith2019TreeSearch). Specify "profile" to employ an approximation of profile parsimony \insertCiteFaith2001TreeSearch.
...	unused; allows additional parameters specified within ... to be received by the function without throwing an error.

Value

TreeLength() returns a numeric vector containing the score for each tree in tree.

Author(s)

Martin R. Smith (using Morphy C library, by Martin Brazeau)

References

\insertAllCited

See Also

• Conduct tree search using MaximizeParsimony() (command line), EasyTrees() (graphical user interface), or TreeSearch() (custom optimality criteria).

• See score for each character: CharacterLength().

Other tree scoring: CharacterLength(), LengthAdded(), MinimumLength(), MorphyTreeLength(), TaxonInfluence()

Examples

data("inapplicable.datasets")
tree <- TreeTools::BalancedTree(inapplicable.phyData[[1]])
TreeLength(tree, inapplicable.phyData[[1]])
TreeLength(tree, inapplicable.phyData[[1]], concavity = 10)
TreeLength(tree, inapplicable.phyData[[1]], concavity = "profile")
TreeLength(5, inapplicable.phyData[[1]])

TreeSearch documentation built on April 11, 2025, 5:49 p.m.