enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Variance - Wikipedia

    en.wikipedia.org/wiki/Variance

    The use of the term n − 1 is called Bessel's correction, and it is also used in sample covariance and the sample standard deviation (the square root of variance). The square root is a concave function and thus introduces negative bias (by Jensen's inequality ), which depends on the distribution, and thus the corrected sample standard ...

  3. Statistical dispersion - Wikipedia

    en.wikipedia.org/wiki/Statistical_dispersion

    In statistics, dispersion (also called variability, scatter, or spread) is the extent to which a distribution is stretched or squeezed. [1] Common examples of measures of statistical dispersion are the variance , standard deviation , and interquartile range .

  4. Standard deviation - Wikipedia

    en.wikipedia.org/wiki/Standard_deviation

    In statistics, the standard deviation is a measure of the amount of variation of the values of a variable about its mean. [1] A low standard deviation indicates that the values tend to be close to the mean (also called the expected value ) of the set, while a high standard deviation indicates that the values are spread out over a wider range.

  5. Calculus of variations - Wikipedia

    en.wikipedia.org/wiki/Calculus_of_Variations

    Calculus of variations is concerned with variations of functionals, which are small changes in the functional's value due to small changes in the function that is its argument. The first variation [l] is defined as the linear part of the change in the functional, and the second variation [m] is defined as the quadratic part. [22]

  6. Average absolute deviation - Wikipedia

    en.wikipedia.org/wiki/Average_absolute_deviation

    The term "average absolute deviation" does not uniquely identify a measure of statistical dispersion, as there are several measures that can be used to measure absolute deviations, and there are several measures of central tendency that can be used as well. Thus, to uniquely identify the absolute deviation it is necessary to specify both the ...

  7. Total variation - Wikipedia

    en.wikipedia.org/wiki/Total_variation

    In mathematics, the total variation identifies several slightly different concepts, related to the (local or global) structure of the codomain of a function or a measure.For a real-valued continuous function f, defined on an interval [a, b] ⊂ R, its total variation on the interval of definition is a measure of the one-dimensional arclength of the curve with parametric equation x ↦ f(x ...

  8. Variable (mathematics) - Wikipedia

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

    In mathematics, a variable (from Latin variabilis, "changeable") is a symbol, typically a letter, that refers to an unspecified mathematical object. [ 1 ] [ 2 ] [ 3 ] One says colloquially that the variable represents or denotes the object, and that any valid candidate for the object is the value of the variable.

  9. Variational principle - Wikipedia

    en.wikipedia.org/wiki/Variational_principle

    In science and especially in mathematical studies, a variational principle is one that enables a problem to be solved using calculus of variations, which concerns finding functions that optimize the values of quantities that depend on those functions.