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The search for similarity and dissimilarity measures on phylogenetic trees has been motivated by the computation of consensus trees, the search by similarity in phylogenetic databases, and the assessment of clustering results in…

Populations and Evolution · Quantitative Biology 2011-11-09 Francesc Rossello , Gabriel Valiente

We propose a new arithmetic for non-empty rooted unordered trees simply called trees. After discussing tree representation and enumeration, we define the operations of tree addition, multiplication and stretch, prove their properties, and…

Discrete Mathematics · Computer Science 2016-02-02 Fabrizio Luccio

Dynamic trees are mixtures of tree structured belief networks. They solve some of the problems of fixed tree networks at the cost of making exact inference intractable. For this reason approximate methods such as sampling or mean field…

Machine Learning · Computer Science 2013-01-18 Amos J. Storkey

We study computationally-hard fundamental motion planning problems where the goal is to translate $k$ axis-aligned rectangular robots from their initial positions to their final positions without collision, and with the minimum number of…

Computational Geometry · Computer Science 2024-03-05 Iyad Kanj , Salman Parsa

An important problem in geometric computing is defining and computing similarity between two geometric shapes, e.g. point sets, curves and surfaces, etc. Important geometric and topological information of many shapes can be captured by…

Computational Geometry · Computer Science 2015-08-17 Hangjun Xu

Computing the similarity between two data points plays a vital role in many machine learning algorithms. Metric learning has the aim of learning a good metric automatically from data. Most existing studies on metric learning for…

Machine Learning · Computer Science 2020-03-10 Hikaru Shindo , Masaaki Nishino , Yasuaki Kobayashi , Akihiro Yamamoto

Three standard subtree transfer operations for binary trees, used in particular for phylogenetic trees, are: tree bisection and reconnection ($TBR$), subtree prune and regraft ($SPR$) and rooted subtree prune and regraft ($rSPR$). For a…

Combinatorics · Mathematics 2015-09-03 Ross Atkins , Colin McDiarmid

We show that CSP is fixed-parameter tractable when parameterized by the treewidth of a backdoor into any tractable CSP problem over a finite constraint language. This result combines the two prominent approaches for achieving tractability…

Data Structures and Algorithms · Computer Science 2016-10-12 Robert Ganian , M. S. Ramanujan , Stefan Szeider

In this work we study the interleaving distance between merge trees from a combinatorial point of view. We use a particular type of matching between trees to obtain a novel formulation of the distance. With such formulation, we tackle the…

Combinatorics · Mathematics 2024-11-11 Matteo Pegoraro

Reachability analysis is a powerful tool when it comes to capturing the behaviour, thus verifying the safety, of autonomous systems. However, general-purpose methods, such as Hamilton-Jacobi approaches, suffer from the curse of…

Optimization and Control · Mathematics 2022-10-27 Alessandro Alla , Peter M. Dower , Vincent Liu

We prove cyclic sieving phenomena satisfied by corner-rooted plane trees (alias ordered trees). The sets of rooted plane trees that we consider are: (1) all trees with $n$ nodes; (2) all trees with $n$ nodes and $k$ leaves; (3) all trees…

Combinatorics · Mathematics 2025-12-23 Mireille Bousquet-Mélou , Christian Krattenthaler

We consider the classical tree edit distance between ordered labeled trees, which is defined as the minimum-cost sequence of node edit operations that transform one tree into another. The state-of-the-art solutions for the tree edit…

Databases · Computer Science 2012-01-04 Mateusz Pawlik , Nikolaus Augsten

Let T be a triangulation of a simple polygon. A flip in T is the operation of removing one diagonal of T and adding a different one such that the resulting graph is again a triangulation. The flip distance between two triangulations is the…

Computational Geometry · Computer Science 2017-11-21 Oswin Aichholzer , Wolfgang Mulzer , Alexander Pilz

An evolutionary tree is a rooted tree where each internal vertex has at least two children and where the leaves are labeled with distinct symbols representing species. Evolutionary trees are useful for modeling the evolutionary history of…

Computational Engineering, Finance, and Science · Computer Science 2007-05-23 Ming-Yang Kao

The quartet distance is a measure of similarity used to compare two unrooted phylogenetic trees on the same set of $n$ leaves, defined as the number of subsets of four leaves related by a different topology in both trees. After a series of…

Data Structures and Algorithms · Computer Science 2020-12-03 Bartłomiej Dudek , Paweł Gawrychowski

The rotor walk on a graph is a deterministic analogue of random walk. Each vertex is equipped with a rotor, which routes the walker to the neighbouring vertices in a fixed cyclic order on successive visits. We consider rotor walk on an…

Combinatorics · Mathematics 2010-09-27 Omer Angel , Alexander E. Holroyd

There exists a bijection between one stack sortable permutations --permutations which avoid the pattern 231-- and planar trees. We define an edit distance between permutations which is coherent with the standard edit distance between trees.…

Combinatorics · Mathematics 2007-05-23 Anne Micheli , Dominique Rossin

We describe a kernel of size 9k-8 for the NP-hard problem of computing the Tree Bisection and Reconnect (TBR) distance k between two unrooted binary phylogenetic trees. We achieve this by extending the existing portfolio of reduction rules…

Data Structures and Algorithms · Computer Science 2022-09-21 Steven Kelk , Simone Linz , Ruben Meuwese

The Gromov-Hausdorff (GH) distance is a natural way to measure distance between two metric spaces. We prove that it is $\mathrm{NP}$-hard to approximate the Gromov-Hausdorff distance better than a factor of $3$ for geodesic metrics on a…

Computational Geometry · Computer Science 2017-06-14 Pankaj K. Agarwal , Kyle Fox , Abhinandan Nath , Anastasios Sidiropoulos , Yusu Wang

We consider the numerical taxonomy problem of fitting a positive distance function ${D:{S\choose 2}\rightarrow \mathbb R_{>0}}$ by a tree metric. We want a tree $T$ with positive edge weights and including $S$ among the vertices so that…

Data Structures and Algorithms · Computer Science 2022-03-14 Vincent Cohen-Addad , Debarati Das , Evangelos Kipouridis , Nikos Parotsidis , Mikkel Thorup