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Related papers: The Application of kd-tree in Astronomy

200 papers

Approximate nearest neighbor algorithms are used to speed up nearest neighbor search in a wide array of applications. However, current indexing methods feature several hyperparameters that need to be tuned to reach an acceptable…

Data Structures and Algorithms · Computer Science 2019-04-25 Elias Jääsaari , Ville Hyvönen , Teemu Roos

Random Indexing (RI) K-tree is the combination of two algorithms for clustering. Many large scale problems exist in document clustering. RI K-tree scales well with large inputs due to its low complexity. It also exhibits features that are…

Information Retrieval · Computer Science 2010-02-02 Christopher M. De Vries , Lance De Vine , Shlomo Geva

A concept of the ground-based optical astronomical observations efficiency is considered in this paper. We believe that a telescope efficiency can be increased by properly allocating observation tasks with respect to the current environment…

Instrumentation and Methods for Astrophysics · Physics 2018-06-26 Matwey V. Kornilov

In particle simulations, the weights of particles determine how many physical particles they represent. Adaptively adjusting these weights can greatly improve the efficiency of the simulation, without creating severe nonphysical artifacts.…

Computational Physics · Physics 2014-11-05 Jannis Teunissen , Ute Ebert

Computing $k$-Nearest Neighbors (KNN) is one of the core kernels used in many machine learning, data mining and scientific computing applications. Although kd-tree based $O(\log n)$ algorithms have been proposed for computing KNN, due to…

Distributed, Parallel, and Cluster Computing · Computer Science 2016-11-17 Md. Mostofa Ali Patwary , Nadathur Rajagopalan Satish , Narayanan Sundaram , Jialin Liu , Peter Sadowski , Evan Racah , Suren Byna , Craig Tull , Wahid Bhimji , Prabhat , Pradeep Dubey

Trees or rooted trees have been generously studied in the literature. A forest is a set of trees or rooted trees. Here we give recurrence relations between the number of some kind of rooted forest with $k$ roots and that with $k+1$ roots on…

Combinatorics · Mathematics 2017-02-08 Song Guo , Victor J. W. Guo

This work emphasizes that heterogeneity, diversity, discontinuity, and discreteness in data is to be exploited in classification and regression problems. A global a priori model may not be desirable. For data analytics in cosmology, this is…

Instrumentation and Methods for Astrophysics · Physics 2018-04-10 Fionn Murtagh

Given a set S of n \geq d points in general position in R^d, a random hyperplane split is obtained by sampling d points uniformly at random without replacement from S and splitting based on their affine hull. A random hyperplane search tree…

Computational Geometry · Computer Science 2011-06-03 Luc Devroye , James King

Dual-tree algorithms are a widely used class of branch-and-bound algorithms. Unfortunately, developing dual-tree algorithms for use with different trees and problems is often complex and burdensome. We introduce a four-part logical split:…

Data Structures and Algorithms · Computer Science 2013-04-17 Ryan R. Curtin , William B. March , Parikshit Ram , David V. Anderson , Alexander G. Gray , Charles L. Isbell

Context: In astronomy, new approaches to process and analyze the exponentially increasing amount of data are inevitable. While classical approaches (e.g. template fitting) are fine for objects of well-known classes, alternative techniques…

Astrophysics of Galaxies · Physics 2016-08-08 S. D. Kügler , K. Polsterer , M. Hoecker

Obtaining accurate photometric redshift estimations is an important aspect of cosmology, remaining a prerequisite of many analyses. In creating novel methods to produce redshift estimations, there has been a shift towards using machine…

Instrumentation and Methods for Astrophysics · Physics 2021-07-07 Ben Henghes , Connor Pettitt , Jeyan Thiyagalingam , Tony Hey , Ofer Lahav

Cartesian tree matching is the problem of finding all substrings of a given text which have the same Cartesian trees as that of a given pattern. So far there is one linear-time solution for Cartesian tree matching, which is based on the KMP…

Data Structures and Algorithms · Computer Science 2019-08-15 Siwoo Song , Cheol Ryu , Simone Faro , Thierry Lecroq , Kunsoo Park

Precision photometric redshifts will be essential for extracting cosmological parameters from the next generation of wide-area imaging surveys. In this paper we introduce a photometric redshift algorithm, ArborZ, based on the…

Cosmology and Nongalactic Astrophysics · Physics 2010-05-06 David W. Gerdes , Adam J. Sypniewski , Timothy A. McKay , Jiangang Hao , Matthew R. Weis , Risa H. Wechsler , Michael T. Busha

Spatial data fusion is a bottleneck when it meets the scale of 10 billion records. Cross-matching celestial catalogs is just one example of this. To challenge this, we present a framework that enables efficient cross-matching using Learned…

Instrumentation and Methods for Astrophysics · Physics 2025-04-16 Phu-Minh Lam , Dongwei Fan , Hongbo Wei , Jun Wang , Yu Zhou , Qi Ma , Baolong Zhang , Xiazhao Zhang , Yongheng Wang

The contributions of the paper span theoretical and implementational results. First, we prove that Kd-trees can be extended to spaces in which the distance is measured with an arbitrary Bregman divergence. Perhaps surprisingly, this shows…

Computational Geometry · Computer Science 2025-02-20 Tuyen Pham , Hubert Wagner

We present an empirical analysis of data structures for approximate nearest neighbor searching. We compare the well-known optimized kd-tree splitting method against two alternative splitting methods. The first, called the sliding-midpoint…

Computational Geometry · Computer Science 2007-05-23 Songrit Maneewongvatana , David M. Mount

We present recent results from the Laboratory for Cosmological Data Mining (http://lcdm.astro.uiuc.edu) at the National Center for Supercomputing Applications (NCSA) to provide robust classifications and photometric redshifts for objects in…

Astrophysics · Physics 2007-10-25 Nicholas M. Ball , Robert J. Brunner , Adam D. Myers

This review summarizes popular unsupervised learning methods, and gives an overview of their past, current, and future uses in astronomy. Unsupervised learning aims to organise the information content of a dataset, in such a way that…

Instrumentation and Methods for Astrophysics · Physics 2024-06-26 Sotiria Fotopoulou

The kd-tree is a fundamental tool in computer science. Among other applications, the application of kd-tree search (by the tree method) to the fast evaluation of particle interactions and neighbor search is highly important, since the…

Instrumentation and Methods for Astrophysics · Physics 2011-12-21 Naohito Nakasato

In this paper we presented the algorithm designed to efficient coordinate cross-match of objects in the modern massive astronomical catalogues. Preliminary data sort in the existed catalogues provides the opportunity for coordinate…

Instrumentation and Methods for Astrophysics · Physics 2018-05-28 Volodymyr Akhmetov , Artem Dmytrenko , Sergii Khlamov