11.3 Eigenvalues and Eigenvectors of a Tridiagonal Matrix 469
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Eigenvalues and Eigenvectors of Tridiagonal Matrices∗
Electronic Journal of Linear Algebra ISSN 1081-3810 A publication of the International Linear Algebra Society Volume 15, pp. 115-133, April 2006 ELA http://math.technion.ac.il/iic/ela EIGENVALUES AND EIGENVECTORS OF TRIDIAGONAL MATRICES∗ SAID KOUACHI† Abstract. This paper is continuation of previous work by the present author, where explicit formulas for the eigenvalues associated with several tridiagonal matrices were given. In this paper the associated eigenvectors are calculated explicitly. As a consequence, a result obtained by Wen- Chyuan Yueh and independently by S. Kouachi, concerning the eigenvalues and in particular the corresponding eigenvectors of tridiagonal matrices, is generalized. Expressions for the eigenvectors are obtained that differ completely from those obtained by Yueh. The techniques used herein are based on theory of recurrent sequences. The entries situated on each of the secondary diagonals are not necessary equal as was the case considered by Yueh. Key words. Eigenvectors, Tridiagonal matrices. AMS subject classifications. 15A18. 1. Introduction. The subject of this paper is diagonalization of tridiagonal matrices. We generalize a result obtained in [5] concerning the eigenvalues and the corresponding eigenvectors of several tridiagonal matrices. We consider tridiagonal matrices of the form −α + bc1 00 ... 0 a1 bc2 0 ... 0 .. .. 0 a2 b . An = , (1) .. .. .. 00. 0 . .. .. .. . cn−1 0 ... ... 0 an−1 −β + b n−1 n−1 ∞ where {aj}j=1 and {cj}j=1 are two finite subsequences of the sequences {aj}j=1 and ∞ {cj}j=1 of the field of complex numbers C, respectively, and α, β and b are complex numbers. We suppose that 2 d1, if j is odd ajcj = 2 j =1, 2, ..., (2) d2, if j is even where d 1 and d2 are complex numbers. -
Parametrizations of K-Nonnegative Matrices
Parametrizations of k-Nonnegative Matrices Anna Brosowsky, Neeraja Kulkarni, Alex Mason, Joe Suk, Ewin Tang∗ October 2, 2017 Abstract Totally nonnegative (positive) matrices are matrices whose minors are all nonnegative (positive). We generalize the notion of total nonnegativity, as follows. A k-nonnegative (resp. k-positive) matrix has all minors of size k or less nonnegative (resp. positive). We give a generating set for the semigroup of k-nonnegative matrices, as well as relations for certain special cases, i.e. the k = n − 1 and k = n − 2 unitriangular cases. In the above two cases, we find that the set of k-nonnegative matrices can be partitioned into cells, analogous to the Bruhat cells of totally nonnegative matrices, based on their factorizations into generators. We will show that these cells, like the Bruhat cells, are homeomorphic to open balls, and we prove some results about the topological structure of the closure of these cells, and in fact, in the latter case, the cells form a Bruhat-like CW complex. We also give a family of minimal k-positivity tests which form sub-cluster algebras of the total positivity test cluster algebra. We describe ways to jump between these tests, and give an alternate description of some tests as double wiring diagrams. 1 Introduction A totally nonnegative (respectively totally positive) matrix is a matrix whose minors are all nonnegative (respectively positive). Total positivity and nonnegativity are well-studied phenomena and arise in areas such as planar networks, combinatorics, dynamics, statistics and probability. The study of total positivity and total nonnegativity admit many varied applications, some of which are explored in “Totally Nonnegative Matrices” by Fallat and Johnson [5]. -
Life As a Developer of Numerical Software
A Brief History of Numerical Libraries Sven Hammarling NAG Ltd, Oxford & University of Manchester First – Something about Jack Jack’s thesis (August 1980) 30 years ago! TOMS Algorithm 589 Small Selection of Jack’s Projects • Netlib and other software repositories • NA Digest and na-net • PVM and MPI • TOP 500 and computer benchmarking • NetSolve and other distributed computing projects • Numerical linear algebra Onto the Rest of the Talk! Rough Outline • History and influences • Fortran • Floating Point Arithmetic • Libraries and packages • Proceedings and Books • Summary Ada Lovelace (Countess Lovelace) Born Augusta Ada Byron 1815 – 1852 The language Ada was named after her “Is thy face like thy mother’s, my fair child! Ada! sole daughter of my house and of my heart? When last I saw thy young blue eyes they smiled, And then we parted,-not as now we part, but with a hope” Childe Harold’s Pilgramage, Lord Byron Program for the Bernoulli Numbers Manchester Baby, 21 June 1948 (Replica) 19 Kilburn/Tootill Program to compute the highest proper factor 218 218 took 52 minutes 1.5 million instructions 3.5 million store accesses First published numerical library, 1951 First use of the word subroutine? Quality Numerical Software • Should be: – Numerically stable, with measures of quality of solution – Reliable and robust – Accompanied by test software – Useful and user friendly with example programs – Fully documented – Portable – Efficient “I have little doubt that about 80 per cent. of all the results printed from the computer are in error to a much greater extent than the user would believe, ...'' Leslie Fox, IMA Bulletin, 1971 “Giving business people spreadsheets is like giving children circular saws. -
Numerical and Parallel Libraries
Numerical and Parallel Libraries Uwe Küster University of Stuttgart High-Performance Computing-Center Stuttgart (HLRS) www.hlrs.de Uwe Küster Slide 1 Höchstleistungsrechenzentrum Stuttgart Numerical Libraries Public Domain commercial vendor specific Uwe Küster Slide 2 Höchstleistungsrechenzentrum Stuttgart 33. — Numerical and Parallel Libraries — 33. 33-1 Overview • numerical libraries for linear systems – dense – sparse •FFT • support for parallelization Uwe Küster Slide 3 Höchstleistungsrechenzentrum Stuttgart Public Domain Lapack-3 linear equations, eigenproblems BLAS fast linear kernels Linpack linear equations Eispack eigenproblems Slatec old library, large functionality Quadpack numerical quadrature Itpack sparse problems pim linear systems PETSc linear systems Netlib Server best server http://www.netlib.org/utk/papers/iterative-survey/packages.html Uwe Küster Slide 4 Höchstleistungsrechenzentrum Stuttgart 33. — Numerical and Parallel Libraries — 33. 33-2 netlib server for all public domain numerical programs and libraries http://www.netlib.org Uwe Küster Slide 5 Höchstleistungsrechenzentrum Stuttgart Contents of netlib access aicm alliant amos ampl anl-reports apollo atlas benchmark bib bibnet bihar blacs blas blast bmp c c++ cephes chammp cheney-kincaid clapack commercial confdb conformal contin control crc cumulvs ddsv dierckx diffpack domino eispack elefunt env f2c fdlibm fftpack fishpack fitpack floppy fmm fn fortran fortran-m fp gcv gmat gnu go graphics harwell hence hompack hpf hypercube ieeecss ijsa image intercom itpack -
(Hessenberg) Eigenvalue-Eigenmatrix Relations∗
(HESSENBERG) EIGENVALUE-EIGENMATRIX RELATIONS∗ JENS-PETER M. ZEMKE† Abstract. Explicit relations between eigenvalues, eigenmatrix entries and matrix elements are derived. First, a general, theoretical result based on the Taylor expansion of the adjugate of zI − A on the one hand and explicit knowledge of the Jordan decomposition on the other hand is proven. This result forms the basis for several, more practical and enlightening results tailored to non-derogatory, diagonalizable and normal matrices, respectively. Finally, inherent properties of (upper) Hessenberg, resp. tridiagonal matrix structure are utilized to construct computable relations between eigenvalues, eigenvector components, eigenvalues of principal submatrices and products of lower diagonal elements. Key words. Algebraic eigenvalue problem, eigenvalue-eigenmatrix relations, Jordan normal form, adjugate, principal submatrices, Hessenberg matrices, eigenvector components AMS subject classifications. 15A18 (primary), 15A24, 15A15, 15A57 1. Introduction. Eigenvalues and eigenvectors are defined using the relations Av = vλ and V −1AV = J. (1.1) We speak of a partial eigenvalue problem, when for a given matrix A ∈ Cn×n we seek scalar λ ∈ C and a corresponding nonzero vector v ∈ Cn. The scalar λ is called the eigenvalue and the corresponding vector v is called the eigenvector. We speak of the full or algebraic eigenvalue problem, when for a given matrix A ∈ Cn×n we seek its Jordan normal form J ∈ Cn×n and a corresponding (not necessarily unique) eigenmatrix V ∈ Cn×n. Apart from these constitutional relations, for some classes of structured matrices several more intriguing relations between components of eigenvectors, matrix entries and eigenvalues are known. For example, consider the so-called Jacobi matrices. -
Jack Dongarra: Supercomputing Expert and Mathematical Software Specialist
Biographies Jack Dongarra: Supercomputing Expert and Mathematical Software Specialist Thomas Haigh University of Wisconsin Editor: Thomas Haigh Jack J. Dongarra was born in Chicago in 1950 to a he applied for an internship at nearby Argonne National family of Sicilian immigrants. He remembers himself as Laboratory as part of a program that rewarded a small an undistinguished student during his time at a local group of undergraduates with college credit. Dongarra Catholic elementary school, burdened by undiagnosed credits his success here, against strong competition from dyslexia.Onlylater,inhighschool,didhebeginto students attending far more prestigious schools, to Leff’s connect material from science classes with his love of friendship with Jim Pool who was then associate director taking machines apart and tinkering with them. Inspired of the Applied Mathematics Division at Argonne.2 by his science teacher, he attended Chicago State University and majored in mathematics, thinking that EISPACK this would combine well with education courses to equip Dongarra was supervised by Brian Smith, a young him for a high school teaching career. The first person in researcher whose primary concern at the time was the his family to go to college, he lived at home and worked lab’s EISPACK project. Although budget cuts forced Pool to in a pizza restaurant to cover the cost of his education.1 make substantial layoffs during his time as acting In 1972, during his senior year, a series of chance director of the Applied Mathematics Division in 1970– events reshaped Dongarra’s planned career. On the 1971, he had made a special effort to find funds to suggestion of Harvey Leff, one of his physics professors, protect the project and hire Smith. -
Explicit Inverse of a Tridiagonal (P, R)–Toeplitz Matrix
Explicit inverse of a tridiagonal (p; r){Toeplitz matrix A.M. Encinas, M.J. Jim´enez Departament de Matemtiques Universitat Politcnica de Catalunya Abstract Tridiagonal matrices appears in many contexts in pure and applied mathematics, so the study of the inverse of these matrices becomes of specific interest. In recent years the invertibility of nonsingular tridiagonal matrices has been quite investigated in different fields, not only from the theoretical point of view (either in the framework of linear algebra or in the ambit of numerical analysis), but also due to applications, for instance in the study of sound propagation problems or certain quantum oscillators. However, explicit inverses are known only in a few cases, in particular when the tridiagonal matrix has constant diagonals or the coefficients of these diagonals are subjected to some restrictions like the tridiagonal p{Toeplitz matrices [7], such that their three diagonals are formed by p{periodic sequences. The recent formulae for the inversion of tridiagonal p{Toeplitz matrices are based, more o less directly, on the solution of second order linear difference equations, although most of them use a cumbersome formulation, that in fact don not take into account the periodicity of the coefficients. This contribution presents the explicit inverse of a tridiagonal matrix (p; r){Toeplitz, which diagonal coefficients are in a more general class of sequences than periodic ones, that we have called quasi{periodic sequences. A tridiagonal matrix A = (aij) of order n + 2 is called (p; r){Toeplitz if there exists m 2 N0 such that n + 2 = mp and ai+p;j+p = raij; i; j = 0;:::; (m − 1)p: Equivalently, A is a (p; r){Toeplitz matrix iff k ai+kp;j+kp = r aij; i; j = 0; : : : ; p; k = 0; : : : ; m − 1: We have developed a technique that reduces any linear second order difference equation with periodic or quasi-periodic coefficients to a difference equation of the same kind but with constant coefficients [3]. -
Randnla: Randomized Numerical Linear Algebra
review articles DOI:10.1145/2842602 generation mechanisms—as an algo- Randomization offers new benefits rithmic or computational resource for the develop ment of improved algo- for large-scale linear algebra computations. rithms for fundamental matrix prob- lems such as matrix multiplication, BY PETROS DRINEAS AND MICHAEL W. MAHONEY least-squares (LS) approximation, low- rank matrix approxi mation, and Lapla- cian-based linear equ ation solvers. Randomized Numerical Linear Algebra (RandNLA) is an interdisci- RandNLA: plinary research area that exploits randomization as a computational resource to develop improved algo- rithms for large-scale linear algebra Randomized problems.32 From a foundational per- spective, RandNLA has its roots in theoretical computer science (TCS), with deep connections to mathemat- Numerical ics (convex analysis, probability theory, metric embedding theory) and applied mathematics (scientific computing, signal processing, numerical linear Linear algebra). From an applied perspec- tive, RandNLA is a vital new tool for machine learning, statistics, and data analysis. Well-engineered implemen- Algebra tations have already outperformed highly optimized software libraries for ubiquitous problems such as least- squares,4,35 with good scalability in par- allel and distributed environments. 52 Moreover, RandNLA promises a sound algorithmic and statistical foundation for modern large-scale data analysis. MATRICES ARE UBIQUITOUS in computer science, statistics, and applied mathematics. An m × n key insights matrix can encode information about m objects ˽ Randomization isn’t just used to model noise in data; it can be a powerful (each described by n features), or the behavior of a computational resource to develop discretized differential operator on a finite element algorithms with improved running times and stability properties as well as mesh; an n × n positive-definite matrix can encode algorithms that are more interpretable in the correlations between all pairs of n objects, or the downstream data science applications. -
Determinant Formulas and Cofactors
Determinant formulas and cofactors Now that we know the properties of the determinant, it’s time to learn some (rather messy) formulas for computing it. Formula for the determinant We know that the determinant has the following three properties: 1. det I = 1 2. Exchanging rows reverses the sign of the determinant. 3. The determinant is linear in each row separately. Last class we listed seven consequences of these properties. We can use these ten properties to find a formula for the determinant of a 2 by 2 matrix: � � � � � � � a b � � a 0 � � 0 b � � � = � � + � � � c d � � c d � � c d � � � � � � � � � � a 0 � � a 0 � � 0 b � � 0 b � = � � + � � + � � + � � � c 0 � � 0 d � � c 0 � � 0 d � = 0 + ad + (−cb) + 0 = ad − bc. By applying property 3 to separate the individual entries of each row we could get a formula for any other square matrix. However, for a 3 by 3 matrix we’ll have to add the determinants of twenty seven different matrices! Many of those determinants are zero. The non-zero pieces are: � � � � � � � � � a a a � � a 0 0 � � a 0 0 � � 0 a 0 � � 11 12 13 � � 11 � � 11 � � 12 � � a21 a22 a23 � = � 0 a22 0 � + � 0 0 a23 � + � a21 0 0 � � � � � � � � � � a31 a32 a33 � � 0 0 a33 � � 0 a32 0 � � 0 0 a33 � � � � � � � � 0 a 0 � � 0 0 a � � 0 0 a � � 12 � � 13 � � 13 � + � 0 0 a23 � + � a21 0 0 � + � 0 a22 0 � � � � � � � � a31 0 0 � � 0 a32 0 � � a31 0 0 � = a11 a22a33 − a11a23 a33 − a12a21a33 +a12a23a31 + a13 a21a32 − a13a22a31. Each of the non-zero pieces has one entry from each row in each column, as in a permutation matrix. -
The Unsymmetric Eigenvalue Problem
Jim Lambers CME 335 Spring Quarter 2010-11 Lecture 4 Supplemental Notes The Unsymmetric Eigenvalue Problem Properties and Decompositions Let A be an n × n matrix. A nonzero vector x is called an eigenvector of A if there exists a scalar λ such that Ax = λx: The scalar λ is called an eigenvalue of A, and we say that x is an eigenvector of A corresponding to λ. We see that an eigenvector of A is a vector for which matrix-vector multiplication with A is equivalent to scalar multiplication by λ. We say that a nonzero vector y is a left eigenvector of A if there exists a scalar λ such that λyH = yH A: The superscript H refers to the Hermitian transpose, which includes transposition and complex conjugation. That is, for any matrix A, AH = AT . An eigenvector of A, as defined above, is sometimes called a right eigenvector of A, to distinguish from a left eigenvector. It can be seen that if y is a left eigenvector of A with eigenvalue λ, then y is also a right eigenvector of AH , with eigenvalue λ. Because x is nonzero, it follows that if x is an eigenvector of A, then the matrix A − λI is singular, where λ is the corresponding eigenvalue. Therefore, λ satisfies the equation det(A − λI) = 0: The expression det(A−λI) is a polynomial of degree n in λ, and therefore is called the characteristic polynomial of A (eigenvalues are sometimes called characteristic values). It follows from the fact that the eigenvalues of A are the roots of the characteristic polynomial that A has n eigenvalues, which can repeat, and can also be complex, even if A is real. -
Sparse Linear Systems Section 4.2 – Banded Matrices
Band Systems Tridiagonal Systems Cyclic Reduction Parallel Numerical Algorithms Chapter 4 – Sparse Linear Systems Section 4.2 – Banded Matrices Michael T. Heath and Edgar Solomonik Department of Computer Science University of Illinois at Urbana-Champaign CS 554 / CSE 512 Michael T. Heath and Edgar Solomonik Parallel Numerical Algorithms 1 / 28 Band Systems Tridiagonal Systems Cyclic Reduction Outline 1 Band Systems 2 Tridiagonal Systems 3 Cyclic Reduction Michael T. Heath and Edgar Solomonik Parallel Numerical Algorithms 2 / 28 Band Systems Tridiagonal Systems Cyclic Reduction Banded Linear Systems Bandwidth (or semibandwidth) of n × n matrix A is smallest value w such that aij = 0 for all ji − jj > w Matrix is banded if w n If w p, then minor modifications of parallel algorithms for dense LU or Cholesky factorization are reasonably efficient for solving banded linear system Ax = b If w / p, then standard parallel algorithms for LU or Cholesky factorization utilize few processors and are very inefficient Michael T. Heath and Edgar Solomonik Parallel Numerical Algorithms 3 / 28 Band Systems Tridiagonal Systems Cyclic Reduction Narrow Banded Linear Systems More efficient parallel algorithms for narrow banded linear systems are based on divide-and-conquer approach in which band is partitioned into multiple pieces that are processed simultaneously Reordering matrix by nested dissection is one example of this approach Because of fill, such methods generally require more total work than best serial algorithm for system with dense band We will illustrate for tridiagonal linear systems, for which w = 1, and will assume pivoting is not needed for stability (e.g., matrix is diagonally dominant or symmetric positive definite) Michael T. -
Eigenvalues of a Special Tridiagonal Matrix
Eigenvalues of a Special Tridiagonal Matrix Alexander De Serre Rothney∗ October 10, 2013 Abstract In this paper we consider a special tridiagonal test matrix. We prove that its eigenvalues are the even integers 2;:::; 2n and show its relationship with the famous Kac-Sylvester tridiagonal matrix. 1 Introduction We begin with a quick overview of the theory of symmetric tridiagonal matrices, that is, we detail a few basic facts about tridiagonal matrices. In particular, we describe the symmetrization process of a tridiagonal matrix as well as the orthogonal polynomials that arise from the characteristic polynomials of said matrices. Definition 1.1. A tridiagonal matrix, Tn, is of the form: 2a1 b1 0 ::: 0 3 6 :: :: : 7 6c1 a2 : : : 7 6 7 6 :: :: :: 7 Tn = 6 0 : : : 0 7 ; (1.1) 6 7 6 : :: :: 7 4 : : : an−1 bn−15 0 ::: 0 cn−1 an where entries below the subdiagonal and above the superdiagonal are zero. If bi 6= 0 for i = 1; : : : ; n − 1 and ci 6= 0 for i = 1; : : : ; n − 1, Tn is called a Jacobi matrix. In this paper we will use a more compact notation and only describe the subdiagonal, diagonal, and superdiagonal (where appropriate). For example, Tn can be rewritten as: 0 1 b1 : : : bn−1 Tn = @ a1 a2 : : : an−1 an A : (1.2) c1 : : : cn−1 ∗Bishop's University, Sherbrooke, Quebec, Canada 1 Note that the study of symmetric tridiagonal matrices is sufficient for our purpose as any Jacobi matrix with bici > 0 8i can be symmetrized through a similarity transformation: 0 p p 1 b1c1 ::: bn−1cn−1 −1 An = Dn TnDn = @ a1 a2 : : : an−1 an A ; (1.3) p p b1c1 ::: bn−1cn−1 r cici+1 ··· cn−1 where Dn = diag(γ1; : : : ; γn) and γi = .