INDEX

Abstract algebra, 27, 32

Adjoint matrices, defined, 87, 98; see also Hermitian matrices

Associativity, 15, 27, 28

Bandwidths of matrices, 208–15

Bilinear form, 104

Binomial coefficient, asymptotic form for, 227

Biorthogonality, principle of, 187

Canonical diagonalization of Hermitian matrices, 100

Canonical forms:

    diagonal, 75–79

    Jordan, 68, 121–39

      numerical instability of, 232–33

Cauchy-Schwarz inequality, 84–85, 165

Cayley-Hamilton theorem, 113–14, 127–31

Characteristic equation, 68, 71–72

Column expansion, 10–13

Column vectors, defined, 2

Commutativity, 15–16, 27, 28

Companion matrix, 75

Complex numbers, as field, 27–30, 32

Condition-number of a matrix, 174–77

    defined, 175

Conservation of energy, law of, 104–5

Convex bodies, vector norms and, 171–73

Courant minimax theorem, 146–18

Cramer’s rule, 19, 194

Derivative of a determinant, 23–24

Determinants, 1–24

    defined, 3–4

    derivatives of, 23–24

    evaluation of rank by, 43–47

    of matrix products, 20–23

    properties of, 5–9

    Vandermonde’s, 12–13

    as volumes, 153–57

Diagonal canonical form, 75–79

Diagonalization:

    canonical, of Hermitian matrices, 100

    simultaneous, of two quadratic forms, 103–8

Differential equations, matrix analysis of, 57–70

Dimension of a linear space, 33–37

    defined, 35

    rank as, 40

Disjoint components of Gershgorin circles, 162

Distributivity, 27, 28

Eigensolutions, 67–70

Eigenvalues:

    basis for theory of, 38

    computation of eigenvectors from, 228–31

    defined, 71

    dominant:

      and computation of smaller eigenvalues, 241–50

      defined, 235

      method of iteration for, 235–39

    in left-hand plane, 268–78

    matrices with distinct, 71–74

    multiplicities of, 73, 76–77

    QR method of computing, 279, 283–89

    of similar matrices, 76–77

    solution of differential equations by, 66–70

    trace as sum of, 80–82

    of tridiagonal and Hessenberg matrices, 251–56

    variational properties of, 141–92

    continuous dependence on matrices, 191–92

Eigenvectors:

    basis for theory of, 38

    computation of, from known eigenvalues, 228–31

    defined, 71

    principal axes of ellipsoids as, 95–98

    solution of differential equations by, 66–70

    of tridiagonal and Hessenberg matrices, 251–56

    variational properties of, 141–92

Elimination, method of, 195–202

Ellipsoids, principal axes of, 94–98

Energy, law of conservation of, 104–5

Equal matrices, 14–15

Errors:

    in computed eigenvalues and eigenvectors, 141–92

    rounding, reduction of, 201–2, 217–21

Euclidean space, 32

    rigid motions in, 117–20

Even permutation, defined, 6

Expansions, row and column, 10–13

Exponential matrix, solution of differential equations by, 64–65

Factorization by triangular matrices, 203–8

Fibonacci numbers, 80

Field, defined, 26–27

Finite-dimensional linear vector space, 32

    basis of, 89–93

Francis and Kublanovskaya, method of (QR method), 279, 283–89

Fredholm theory of integral equations, 153

Functional analysis, 32

Gauss-Seidei method, 221–27

Generalized unit sphere, defined, 171

Gershgorin’s theorem, 161–63

    Sturm’s theorem with, 255–56

Gram-Schmidt orthogonalization process, 89–93, 279

Guillemin, E. A., 270

Hadamard’s inequality, 153–57

Hermitian matrices, 98–102, 110

    commuting, 115–17

    factorization and, 206–8

    Hessenberg, eigenvalues and eigenvectors of, 251–58

    positive-definite, 105–8

      determinant criterion for, 152–53

      Gauss-Seidel method and, 224–27

    Rayleigh principle and, 141–45

    Weyl’s theorem and, 157–61

Hessenberg matrices, eigenvalues and eigenvectors of, 251–58

Homogeneous systems:

    defined, 26

    solvability of, 38–42

Householder and Bauer, method of, 251, 258–67

Hurwitz, 268

Inclusion principle, 149–51

    as determinant criterion for positive definiteness, 152–53

Inequalities:

    Cauchy-Schwarz, 84–85, 164

    Hadamard’s, 153–57

    Weyl’s, 157–61

Inhomogeneous systems:

    defined, 26

    fundamental solution of, 60

    general m × n, 48–49

    reduction of, by matrix analysis, 60–62

Inner products, defined, 84, 89, 98

Invariants, 80–82

Inverse matrix, 17–19

Irreducible matrices, 181–84

Iterative methods, 221–27

    for dominant eigenvalues, 235–39

Jordan canonical form, 68, 121–39

    numerical instability of, 232–33

Jordan’s theorem, 122–25, 195

    proof of, 132–39

Keller’s theorem, 224–27

Kronecker delta, 18

Laguerre polynomials, 93

Least-squares solution, 50–55

Linear combinations, 33–37

Linear equations:

    differential, matrix analysis of, 57–70

    direct solution of large systems of, 208–15

    theory of, 26–55

Linear space, see Linear vector space

Linear vector space, 26–32

    basis of, 33–37

      of mutually orthogonal unit vectors, 89–93

    dimension of, 33–37

      rank as dimension, 40

    finite-dimensional, 32

      basis of, 89–93

Linearly dependent and independent vectors, 33–37

Lyapunov’s theorem, 270–72

Mass-spring systems, 103–8

Matrix, defined, 2

Matrix norms, 65

    related, 167–71

      defined, 167–68

Matrix products, determinants of, 20–23

Metric, Riemannian, 164

Minimax theorem, Courant, 146–48

Multiplication of matrices, 15–16, 87

Newton’s method, 256

Nonsingular matrix, defined, 23

Normal equations, 51–55

    defined, 51

Normal matrices, 115–20

    defined, 115

Norms, vector, 163–73

    convex bodies and, 171–73

    regular, defined, 164

Null space, 40, 49

    defined, 39

Numbers as fields, 26–32

Numerical instability of the Jordan canonical form, 232–33

Numerical methods, 194–289

    computation of eigenvectors, 228–31

    direct solution of large systems of linear equations, 208–15

    elimination, 195–202

    factorization by triangular matrices, 203–8

    identification of stable matrices, 268–78

    iterative methods, 221–27

      for dominant eigenvalues, 235–39

      to obtain the smaller eigenvalues, 241–50

    method of Householder and Bauer, 251, 258–67

    QR method, 279, 283–89

    reduction of rounding error, 201–2, 217–21

    with tridiagonal and Hessenberg matrices, 251–58

Odd permutation, defined, 6

Orthogonality:

    defined, 89

    Gram-Schmidt process for, 89–93

    of principal axes of ellipsoids, 95–98

Parallelograms, Hadamard’s inequality and, 154–56

Permutation:

    even, defined, 6

    odd, defined, 6

    sign of the, 4

      theorems on reversal of, 5, 7

Perron’s theorem, 177–82

Perturbation theory, 141–92

    described, 141

Pivotal element, 201–2

Positive and irreducible matrices, 177–84

Positive-definite matrices, 105–8

    determinant criterion for, 152–53

    Gauss-Seidel method and, 224–27

Principal axes of ellipsoids, 94–98

Principal vectors, 125–31

    defined, 125–26

QR method, 279, 283–89

Rank of a matrix, 49

    defined, 40–41

    evaluation of, by determinants, 43–47

Rational numbers, as field, 26

Rayleigh principle, 141–45, 146

Rayleigh quotient, 99, 143

Real numbers, as field, 26, 28, 30, 31, 32

Related matrix-norms, 167–71

    defined, 167–68

Riemannian metric, 164

Rigid motions in Euclidian space, 117–20

Rotation, theory of normal matrices and, 117–20

Rounding error:

    in method of iteration for dominant eigenvalues, 239

    reduction of, 201–2, 217–21

Routh’s theorem, 268–70

Row expansion, 10–13

Row vectors, defined, 2

Rutishauser’s method, 289

Scalars, defined, 27

Schwarz inequality, see Cauchy-Schwarz inequality

Sign of the permutation, 4

    theorems on reversal of, 5, 7

Similar matrices:

    defined, 75

    eigenvalues of, 76–77

Singular matrix, defined, 23

Skew-Hermitian matrices, 115–17

Space, see Euclidean space and Null space

Spectrum, perturbations of, 186–89

Stable matrices, numerical identification of, 268–78

Sturm’s theorem, 254–56

Submatrices:

    defined, 43

    evaluation of rank and, 43–47

Successive over-relaxation, 227

Symmetric matrices, 94–95, 102

    mass and spring matrices as, 105

Trace, 80–82

    defined, 80

Transpose of a matrix, formation of, 6

Triangular matrices:

    accurate unitary reduction to, 279–83

    factorization by, 203–8

    recursion solution of, 195

Triangularization, unitary, 109–14

Tridiagonal matrices, eigenvalues and eigenvectors of, 251–58

Uncoupling property of canonical diagonal form, 78–79

Unit vectors:

    defined, 89

    mutually orthogonal, 89–93

Unitary matrices, 83–88, 102

    accurate reduction of, to triangular form, 279–83

    defined, 87

    as normal matrices, 115–17

Unitary triangularization, 109–14

Unsolvablc systems, least-squares solution of, 50–55

Vandermonde’s determinant, 12–13

Varga, R. S., 227

Variational principles, 141–92

Vector addition, 27–28

Vector norms, 163–73

    convex bodies and, 171–73

    regular, defined, 164

Vector space, see Linear vector space

Vectors, see also Eigenvectors

    defined, 2

    length of, and unitary matrices, 83–87

    linearly dependent and independent, 33–37

    matrices and, 14–16

    principal, 125–31

      defined, 125–26

    unit:

      defined, 89

      mutually orthogonal, 89–93

Volumes, determinants as, 153–57

Weyl’s inequalities, 157–61

Wilkinson, J. II., 218, 279, 284