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  2. Vector calculus identities - Wikipedia

    en.wikipedia.org/wiki/Vector_calculus_identities

    The dotted vector, in this case B, is differentiated, while the (undotted) A is held constant. The utility of the Feynman subscript notation lies in its use in the derivation of vector and tensor derivative identities, as in the following example which uses the algebraic identity C⋅(A×B) = (C×A)⋅B:

  3. Non-negative least squares - Wikipedia

    en.wikipedia.org/wiki/Non-negative_least_squares

    Set x to an all-zero vector of dimension n. Set w = A T (y − Ax). Let w R denote the sub-vector with indexes from R; Main loop: while R ≠ ∅ and max(w R) > ε: Let j in R be the index of max(w R) in w. Add j to P. Remove j from R. Let A P be A restricted to the variables included in P. Let s be vector of same length as x.

  4. Root-finding algorithm - Wikipedia

    en.wikipedia.org/wiki/Root-finding_algorithm

    In numerical analysis, a root-finding algorithm is an algorithm for finding zeros, also called "roots", of continuous functions. A zero of a function f is a number x such that f ( x ) = 0 . As, generally, the zeros of a function cannot be computed exactly nor expressed in closed form , root-finding algorithms provide approximations to zeros.

  5. Gaussian elimination - Wikipedia

    en.wikipedia.org/wiki/Gaussian_elimination

    For each row in a matrix, if the row does not consist of only zeros, then the leftmost nonzero entry is called the leading coefficient (or pivot) of that row. So if two leading coefficients are in the same column, then a row operation of type 3 could be used to make one of those coefficients zero. Then by using the row swapping operation, one ...

  6. Cholesky decomposition - Wikipedia

    en.wikipedia.org/wiki/Cholesky_decomposition

    In linear algebra, the Cholesky decomposition or Cholesky factorization (pronounced / ʃ ə ˈ l ɛ s k i / shə-LES-kee) is a decomposition of a Hermitian, positive-definite matrix into the product of a lower triangular matrix and its conjugate transpose, which is useful for efficient numerical solutions, e.g., Monte Carlo simulations.

  7. Killing vector field - Wikipedia

    en.wikipedia.org/wiki/Killing_vector_field

    Killing vector fields can also be defined on any manifold M (possibly without a metric tensor) if we take any Lie group G acting on it instead of the group of isometries. [8] In this broader sense, a Killing vector field is the pushforward of a right invariant vector field on G by the group action.

  8. Linear span - Wikipedia

    en.wikipedia.org/wiki/Linear_span

    It can be identified with by removing the third components equal to zero. The empty set is a spanning set of {(0, 0, 0)}, since the empty set is a subset of all possible vector spaces in R 3 {\displaystyle \mathbb {R} ^{3}} , and {(0, 0, 0)} is the intersection of all of these vector spaces.

  9. Standard basis - Wikipedia

    en.wikipedia.org/wiki/Standard_basis

    Every vector a in three dimensions is a linear combination of the standard basis vectors i, j and k.. In mathematics, the standard basis (also called natural basis or canonical basis) of a coordinate vector space (such as or ) is the set of vectors, each of whose components are all zero, except one that equals 1. [1]