When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. Sign function - Wikipedia

    en.wikipedia.org/wiki/Sign_function

    The signum function of a real number is a piecewise function which is defined as follows: [1] ⁡:= {<, =, > The law of trichotomy states that every real number must be positive, negative or zero. The signum function denotes which unique category a number falls into by mapping it to one of the values −1 , +1 or 0, which can then be used in ...

  3. Concordant pair - Wikipedia

    en.wikipedia.org/wiki/Concordant_pair

    In statistics, a concordant pair is a pair of observations, each on two variables, (X 1,Y 1) and (X 2,Y 2), having the property that ⁡ = ⁡ (), where "sgn" refers to whether a number is positive, zero, or negative (its sign).

  4. Locally constant function - Wikipedia

    en.wikipedia.org/wiki/Locally_constant_function

    The signum function restricted to the domain {} is locally constant.. In mathematics, a locally constant function is a function from a topological space into a set with the property that around every point of its domain, there exists some neighborhood of that point on which it restricts to a constant function.

  5. Parity of a permutation - Wikipedia

    en.wikipedia.org/wiki/Parity_of_a_permutation

    The sign, signature, or signum of a permutation σ is denoted sgn(σ) and defined as +1 if σ is even and −1 if σ is odd. The signature defines the alternating character of the symmetric group S n .

  6. Step function - Wikipedia

    en.wikipedia.org/wiki/Step_function

    The Heaviside step function is an often-used step function.. A constant function is a trivial example of a step function. Then there is only one interval, =. The sign function sgn(x), which is −1 for negative numbers and +1 for positive numbers, and is the simplest non-constant step function.

  7. Sigmoid function - Wikipedia

    en.wikipedia.org/wiki/Sigmoid_function

    A wide variety of sigmoid functions including the logistic and hyperbolic tangent functions have been used as the activation function of artificial neurons. Sigmoid curves are also common in statistics as cumulative distribution functions (which go from 0 to 1), such as the integrals of the logistic density , the normal density , and Student's ...

  8. Three-way comparison - Wikipedia

    en.wikipedia.org/wiki/Three-way_comparison

    In C, the functions strcmp and memcmp perform a three-way comparison between strings and memory buffers, respectively. They return a negative number when the first argument is lexicographically smaller than the second, zero when the arguments are equal, and a positive number otherwise.

  9. Matrix sign function - Wikipedia

    en.wikipedia.org/wiki/Matrix_sign_function

    The matrix sign function is a generalization of the complex signum function ⁡ = {() >, <, to the matrix valued analogue ⁡ ().Although the sign function is not analytic, the matrix function is well defined for all matrices that have no eigenvalue on the imaginary axis, see for example the Jordan-form-based definition (where the derivatives are all zero).