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  2. Permanent (mathematics) - Wikipedia

    en.wikipedia.org/wiki/Permanent_(mathematics)

    Let Ω(n,k) be the class of all (0, 1)-matrices of order n with each row and column sum equal to k. Every matrix A in this class has perm(A) > 0. [13] The incidence matrices of projective planes are in the class Ω(n 2 + n + 1, n + 1) for n an integer > 1. The permanents corresponding to the smallest projective planes have been calculated.

  3. List of named matrices - Wikipedia

    en.wikipedia.org/wiki/List_of_named_matrices

    Integer matrix: A matrix whose entries are all integers. Logical matrix: A matrix with all entries either 0 or 1. Synonym for (0,1)-matrix, binary matrix or Boolean matrix. Can be used to represent a k-adic relation. Markov matrix: A matrix of non-negative real numbers, such that the entries in each row sum to 1. Metzler matrix

  4. Matrix (mathematics) - Wikipedia

    en.wikipedia.org/wiki/Matrix_(mathematics)

    The identity matrix I n of size n is the n-by-n matrix in which all the elements on the main diagonal are equal to 1 and all other elements are equal to 0, for example, = [], = [], = [] It is a square matrix of order n, and also a special kind of diagonal matrix.

  5. Analytic function of a matrix - Wikipedia

    en.wikipedia.org/wiki/Analytic_function_of_a_matrix

    In mathematics, every analytic function can be used for defining a matrix function that maps square matrices with complex entries to square matrices of the same size. This is used for defining the exponential of a matrix , which is involved in the closed-form solution of systems of linear differential equations .

  6. Matrix calculus - Wikipedia

    en.wikipedia.org/wiki/Matrix_calculus

    In mathematics, matrix calculus is a specialized notation for doing multivariable calculus, especially over spaces of matrices.It collects the various partial derivatives of a single function with respect to many variables, and/or of a multivariate function with respect to a single variable, into vectors and matrices that can be treated as single entities.

  7. Vectorization (mathematics) - Wikipedia

    en.wikipedia.org/wiki/Vectorization_(mathematics)

    For a symmetric matrix A, the vector vec(A) contains more information than is strictly necessary, since the matrix is completely determined by the symmetry together with the lower triangular portion, that is, the n(n + 1)/2 entries on and below the main diagonal. For such matrices, the half-vectorization is

  8. Computing the permanent - Wikipedia

    en.wikipedia.org/wiki/Computing_the_permanent

    The best known [1] general exact algorithm is due to H. J. Ryser ().Ryser's method is based on an inclusion–exclusion formula that can be given [2] as follows: Let be obtained from A by deleting k columns, let () be the product of the row-sums of , and let be the sum of the values of () over all possible .

  9. ♯P-completeness of 01-permanent - Wikipedia

    en.wikipedia.org/wiki/%E2%99%AFP-completeness_of...

    Any square matrix = can be viewed as the adjacency matrix of a directed graph, with representing the weight of the edge from vertex to vertex .Then, the permanent of is equal to the sum of the weights of all cycle-covers of the graph; this is a graph-theoretic interpretation of the permanent.