When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. Marsaglia polar method - Wikipedia

    en.wikipedia.org/wiki/Marsaglia_polar_method

    Standard normal random variables are frequently used in computer science, computational statistics, and in particular, in applications of the Monte Carlo method. The polar method works by choosing random points (x, y) in the square −1 < x < 1, −1 < y < 1 until < = + <, and then returning the required pair of normal random variables as

  3. Normal distribution - Wikipedia

    en.wikipedia.org/wiki/Normal_distribution

    If the characteristic function of some random variable ⁠ ⁠ is of the form () = ⁡ in a neighborhood of zero, where () is a polynomial, then the Marcinkiewicz theorem (named after Józef Marcinkiewicz) asserts that ⁠ ⁠ can be at most a quadratic polynomial, and therefore ⁠ ⁠ is a normal random variable. [33]

  4. MongoDB - Wikipedia

    en.wikipedia.org/wiki/MongoDB

    MongoDB provides three ways to perform aggregation: the aggregation pipeline, the map-reduce function and single-purpose aggregation methods. [40] Map-reduce can be used for batch processing of data and aggregation operations. However, according to MongoDB's documentation, the aggregation pipeline provides better performance for most ...

  5. Log-normal distribution - Wikipedia

    en.wikipedia.org/wiki/Log-normal_distribution

    For example, the log-normal function with such fits well with the size of secondarily produced droplets during droplet impact [56] and the spreading of an epidemic disease. [ 57 ] The value σ = 1 / 6 {\textstyle \sigma =1{\big /}{\sqrt {6}}} is used to provide a probabilistic solution for the Drake equation.

  6. Fold (higher-order function) - Wikipedia

    en.wikipedia.org/wiki/Fold_(higher-order_function)

    Folds can be regarded as consistently replacing the structural components of a data structure with functions and values. Lists, for example, are built up in many functional languages from two primitives: any list is either an empty list, commonly called nil ([]), or is constructed by prefixing an element in front of another list, creating what is called a cons node ( Cons(X1,Cons(X2,Cons ...

  7. Pivotal quantity - Wikipedia

    en.wikipedia.org/wiki/Pivotal_quantity

    One of the simplest pivotal quantities is the z-score.Given a normal distribution with mean and variance , and an observation 'x', the z-score: =, has distribution (,) – a normal distribution with mean 0 and variance 1.

  8. Normalizing constant - Wikipedia

    en.wikipedia.org/wiki/Normalizing_constant

    This is the probability mass function of the Poisson distribution with expected value λ. Note that if the probability density function is a function of various parameters, so too will be its normalizing constant. The parametrised normalizing constant for the Boltzmann distribution plays a central role in statistical mechanics.

  9. Data transformation (statistics) - Wikipedia

    en.wikipedia.org/wiki/Data_transformation...

    From a uniform distribution, we can transform to any distribution with an invertible cumulative distribution function. If G is an invertible cumulative distribution function, and U is a uniformly distributed random variable, then the random variable G −1 (U) has G as its cumulative distribution function.