{"title":"Computing one billion roots using the tangent Graeffe method","authors":"J. Hoeven, M. Monagan","doi":"10.1145/3457341.3457342","DOIUrl":"https://doi.org/10.1145/3457341.3457342","url":null,"abstract":"Let p be a prime of the form p = σ2k + 1 with σ small and let Fp denote the finite field with p elements. Let P(z) be a polynomial of degree d in Fp[z] with d distinct roots in Fp. For p =5 · 255 + 1 we can compute the roots of such polynomials of degree 109. We believe we are the first to factor such polynomials of size one billion. We used a multi-core computer with two 10 core Intel Xeon E5 2680 v2 CPUs and 128 gigabytes of RAM. The factorization takes just under 4,000 seconds on 10 cores and uses 121 gigabytes of RAM. We used the tangent Graeffe root finding algorithm from [27, 19] which is a factor of O(log d) faster than the Cantor-Zassenhaus algorithm. We implemented the tangent Graeffe algorithm in C using our own library of 64 bit integer FFT based in-place polynomial algorithms then parallelized the FFT and main steps using Cilk C. In this article we discuss the steps of the tangent Graeffe algorithm, the sub-algorithms that we used, how we parallelized them, and how we organized the memory so we could factor a polynomial of degree 109. We give both a theoretical and practical comparison of the tangent Graeffe algorithm with the Cantor-Zassenhaus algorithm for root finding. We improve the complexity of the tangent Graeffe algorithm by a factor of 2. We present a new in-place product tree multiplication algorithm that is fully parallelizable. We present some timings comparing our software with Magma's polynomial factorization command. Polynomial root finding over smooth finite fields is a key ingredient for algorithms for sparse polynomial interpolation that are based on geometric sequences. This application was also one of our main motivations for the present work.","PeriodicalId":41965,"journal":{"name":"ACM Communications in Computer Algebra","volume":"54 1","pages":"65 - 85"},"PeriodicalIF":0.1,"publicationDate":"2020-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1145/3457341.3457342","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43840894","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Recent and upcoming events","authors":"Staff","doi":"10.1145/3427218.3427227","DOIUrl":"https://doi.org/10.1145/3427218.3427227","url":null,"abstract":"July 13–16, 2020 The International Congress on Mathematical Software (ICMS 2020) Braunschweig, Germany Virtual conference, due to the COVID-19 pandemic Organizers: General Chair: Michael Joswig (TU Berlin, Germany); Program Chairs: Anna Bigatti (Università di Genova, Italy), Folkmar Bornemann (TU München, Germany), and Jacques Carette (McMaster University, Canada) Website: http://icms-conference.org/2020/","PeriodicalId":41965,"journal":{"name":"ACM Communications in Computer Algebra","volume":"54 1","pages":"62 - 64"},"PeriodicalIF":0.1,"publicationDate":"2020-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1145/3427218.3427227","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44921899","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Marc Härkönen, Benjamin Hollering, Fatemeh Tarashi Kashani, J. Rodriguez
{"title":"Algebraic optimization degree","authors":"Marc Härkönen, Benjamin Hollering, Fatemeh Tarashi Kashani, J. Rodriguez","doi":"10.1145/3427218.3427222","DOIUrl":"https://doi.org/10.1145/3427218.3427222","url":null,"abstract":"The Macaulay2 [5] package AlgebraicOptimization implements methods for determining the algebraic degree of an optimization problem. We describe the structure of an algebraic optimization problem and explain how the methods in this package may be used to determine the respective degrees. Special features include determining Euclidean distance degrees and maximum likelihood degrees. To our knowledge, this is the first comprehensive software package combining different methods in algebraic optimization. The package is available at https://github.com/Macaulay2/Workshop-2020-Cleveland/tree/ISSAC-AlgOpt/alg-stat/AlgebraicOptimization.","PeriodicalId":41965,"journal":{"name":"ACM Communications in Computer Algebra","volume":"54 1","pages":"44 - 48"},"PeriodicalIF":0.1,"publicationDate":"2020-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1145/3427218.3427222","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49269990","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A new Kenzo module for computing the Eilenberg-Moore spectral sequence","authors":"A. Romero, J. Rubio, F. Sergeraert, Markus Szymik","doi":"10.1145/3427218.3427225","DOIUrl":"https://doi.org/10.1145/3427218.3427225","url":null,"abstract":"In this work we present a new module for the computer algebraic topology system Kenzo computing the Eilenberg-Moore spectral sequence of fibrations between spaces with effective homology. These programs can be applied to determine the Eilenberg-Moore spectral sequence of extensions of finitely generated abelian groups.","PeriodicalId":41965,"journal":{"name":"ACM Communications in Computer Algebra","volume":"54 1","pages":"57 - 60"},"PeriodicalIF":0.1,"publicationDate":"2020-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1145/3427218.3427225","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43856465","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tolis Chalkis, Vissarion Fisikopoulos, Panagiotis Repouskos, Elias P. Tsigaridas
{"title":"Sampling the feasible sets of SDPs and volume approximation","authors":"Tolis Chalkis, Vissarion Fisikopoulos, Panagiotis Repouskos, Elias P. Tsigaridas","doi":"10.1145/3457341.3457349","DOIUrl":"https://doi.org/10.1145/3457341.3457349","url":null,"abstract":"We present algorithmic, complexity, and implementation results on the problem of sampling points in the interior and the boundary of a spectrahedron, that is the feasible region of a semidefinite program. Our main tool is random walks. We define and analyze a set of primitive geometric operations that exploits the algebraic properties of spectrahedra and the polynomial eigenvalue problem and leads to the realization of a broad collection of efficient random walks. We demonstrate random walks that experimentally show faster mixing time than the ones used previously for sampling from spectrahedra in theory or applications, for example Hit and Run. Consecutively, the variety of random walks allows us to sample from general probability distributions, for example the family of log-concave distributions which arise frequently in numerous applications. We apply our tools to compute (i) the volume of a spectrahedron and (ii) the expectation of functions coming from robust optimal control. We provide a C++ open source implementation of our methods that scales efficiently up to dimension 200. We illustrate its efficiency on various data sets.","PeriodicalId":41965,"journal":{"name":"ACM Communications in Computer Algebra","volume":"54 1","pages":"114 - 118"},"PeriodicalIF":0.1,"publicationDate":"2020-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1145/3457341.3457349","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43872475","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"International Symposium on Wen-Tsun Wu's Academic Thought and Mathematics Mechanization","authors":"Academy of Mathematics and Systems Science","doi":"10.1145/3388974.3388975","DOIUrl":"https://doi.org/10.1145/3388974.3388975","url":null,"abstract":"During May 12-17, 2019, shall we celebrate the late famous mathematician Wen-Tsun Wu's centenary birthday. Professor Wen-Tsun Wu is one of the most internationally influential mathematicians in China, who brought far-reaching influence on both mathematics and computer research by his great contributions to the field of topology and the opening of the new area of Mathematics Mechanization. His research includes algebraic topology, di.erential topology, mathematics mechanization, algebraic geometry, game theory as well as the history of mathematics. His work has been regarded as among the greatest classical influential results in topology. In late 1970s, he opened the area of mathematics mechanization by the so-called \"Wu method\" which automatically proves geometric theorems using computers and was taken as the pioneer work in automatic reasoning. The symposium focuses on his achievements in topology, mathematics mechanization as well as the history of mathematics, and casts light on their future prospects and potential applications. Specific topics for the symposium include but are not limited to: •Algebraic topology •Automated reasoning •Computational algebraic geometry and optimization •Computational geometry and topology •Computational number theory •Coding theory and cryptology •Di.erential and di.erence algebras •History of mathematics •Polynomial equation solving •Symbolic or symbolic-numeric computation •Applications of mathematical mechanization","PeriodicalId":41965,"journal":{"name":"ACM Communications in Computer Algebra","volume":"53 1","pages":"155 - 181"},"PeriodicalIF":0.1,"publicationDate":"2020-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1145/3388974.3388975","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48504133","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"15 PhD positions in GRAPES","authors":"I. Emiris","doi":"10.1145/3388974.3388978","DOIUrl":"https://doi.org/10.1145/3388974.3388978","url":null,"abstract":"We are pleased to announce 15 open PhD Positions within the new European Network GRAPES: Learning, Processing and Optimising Shapes. GRAPES is a Marie Sk lodowska-Curie Innovative Training Network in the framework of H2020, started on December 1st, 2019, and lasting for 4 years. It includes 11 academic/industrial groups o.ering 15 PhD's, and 6 associated partners; it is coordinated by ATHENA Research & Innovation Center, Greece. GRAPES aims at advancing the state-of-the-art in Mathematics, Computer-Aided Design, and Machine Learning, in order to promote game changing approaches for generating, optimising, and learning 3D shapes, along with a multisectoral training for young researchers, supported by the active participation of SMEs. Recent advances in the above domains have solved numerous tasks concerning multimedia and 2D data. However, automation of 3D geometry processing and analysis lags severely behind, despite their importance in science, technology and everyday life, and some well-understood underlying mathematical principles. Concrete applications include simulation, manufacturing and 3D printing, visualisation and naval design, retrieval and mining, reconstruction and urban planning.","PeriodicalId":41965,"journal":{"name":"ACM Communications in Computer Algebra","volume":"53 1","pages":"189 - 189"},"PeriodicalIF":0.1,"publicationDate":"2020-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1145/3388974.3388978","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44827423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Maple Conference 2019","authors":"J. Gerhard, I. Kotsireas","doi":"10.1145/3388974.3388976","DOIUrl":"https://doi.org/10.1145/3388974.3388976","url":null,"abstract":"The Maple Conference 2019 was held at the University of Waterloo in Waterloo, Ontario, Canada, on October 15 -- October 17, 2019.","PeriodicalId":41965,"journal":{"name":"ACM Communications in Computer Algebra","volume":"53 1","pages":"182 - 182"},"PeriodicalIF":0.1,"publicationDate":"2020-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48440690","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Abstracts of recent doctoral dissertations in computer algebra","authors":"CCA editors","doi":"10.1145/3388974.3388977","DOIUrl":"https://doi.org/10.1145/3388974.3388977","url":null,"abstract":"Each quarter we are pleased to present abstracts of recent doctoral dissertations in Computer Algebra and Symbolic Computation. We encourage all recent Ph.D. graduates who have defended in the past two years (and their supervisors), to submit their abstracts for publication in CCA.","PeriodicalId":41965,"journal":{"name":"ACM Communications in Computer Algebra","volume":"53 1","pages":"183 - 188"},"PeriodicalIF":0.1,"publicationDate":"2020-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1145/3388974.3388977","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47647130","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Ultimate complexity for numerical algorithms","authors":"J. Hoeven, Grégoire Lecerf","doi":"10.1145/3419048.3419049","DOIUrl":"https://doi.org/10.1145/3419048.3419049","url":null,"abstract":"Most numerical algorithms are designed for single or double precision floating point arithmetic, and their complexity is measured in terms of the total number of floating point operations. The resolution of problems with high condition numbers (e.g. when approaching a singularity or degeneracy) may require higher working precisions, in which case it is important to take the precision into account when doing complexity analyses. In this paper, we propose a new \"ultimate complexity\" model, which focuses on analyzing the cost of numerical algorithms for \"sufficiently large\" precisions. As an example application we will present an ultimately softly linear time algorithm for modular composition of univariate polynomials.","PeriodicalId":41965,"journal":{"name":"ACM Communications in Computer Algebra","volume":"54 1","pages":"1 - 13"},"PeriodicalIF":0.1,"publicationDate":"2020-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1145/3419048.3419049","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46249452","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}