enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Covariance and correlation - Wikipedia

    en.wikipedia.org/wiki/Covariance_and_correlation

    where E is the expected value operator. Notably, correlation is dimensionless while covariance is in units obtained by multiplying the units of the two variables. If Y always takes on the same values as X, we have the covariance of a variable with itself (i.e. ), which is called the variance and is more commonly denoted as the square of the ...

  3. Conjugate variables - Wikipedia

    en.wikipedia.org/wiki/Conjugate_variables

    Conjugate variables. Conjugate variables are pairs of variables mathematically defined in such a way that they become Fourier transform duals, [1][2] or more generally are related through Pontryagin duality. The duality relations lead naturally to an uncertainty relation—in physics called the Heisenberg uncertainty principle —between them.

  4. Codomain - Wikipedia

    en.wikipedia.org/wiki/Codomain

    In mathematics, a codomain or set of destination of a function is a set into which all of the output of the function is constrained to fall. It is the set Y in the notation f: X → Y. The term range is sometimes ambiguously used to refer to either the codomain or the image of a function. A codomain is part of a function f if f is defined as a ...

  5. Cauchy boundary condition - Wikipedia

    en.wikipedia.org/wiki/Cauchy_boundary_condition

    e. In mathematics, a Cauchy (French: [koʃi]) boundary condition augments an ordinary differential equation or a partial differential equation with conditions that the solution must satisfy on the boundary; ideally so as to ensure that a unique solution exists. A Cauchy boundary condition specifies both the function value and normal derivative ...

  6. H-infinity methods in control theory - Wikipedia

    en.wikipedia.org/wiki/H-infinity_methods_in...

    The achievable H ∞ norm of the closed loop system is mainly given through the matrix D 11 (when the system P is given in the form (A, B 1, B 2, C 1, C 2, D 11, D 12, D 22, D 21)). There are several ways to come to an H ∞ controller: A Youla-Kucera parametrization of the closed loop often leads to very high-order controller.

  7. Trivial group - Wikipedia

    en.wikipedia.org/wiki/Trivial_group

    In mathematics, a trivial group or zero group is a group consisting of a single element. All such groups are isomorphic, so one often speaks of the trivial group. The single element of the trivial group is the identity element and so it is usually denoted as such: or depending on the context. If the group operation is denoted then it is defined by.

  8. Equidistribution theorem - Wikipedia

    en.wikipedia.org/wiki/Equidistribution_theorem

    In mathematics, the equidistribution theorem is the statement that the sequence. a, 2 a, 3 a, ... mod 1. is uniformly distributed on the circle , when a is an irrational number. It is a special case of the ergodic theorem where one takes the normalized angle measure .

  9. Predicate (mathematical logic) - Wikipedia

    en.wikipedia.org/wiki/Predicate_(mathematical_logic)

    A predicate is a statement or mathematical assertion that contains variables, sometimes referred to as predicate variables, and may be true or false depending on those variables’ value or values. In propositional logic, atomic formulas are sometimes regarded as zero-place predicates. [1] In a sense, these are nullary (i.e. 0- arity) predicates.