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In probability theory, a probability density function (PDF), density function, or density of an absolutely continuous random variable, is a function whose value at any given sample (or point) in the sample space (the set of possible values taken by the random variable) can be interpreted as providing a relative likelihood that the value of the ...
In probability theory, statistics and econometrics, the Burr Type XII distribution or simply the Burr distribution [2] is a continuous probability distribution for a non-negative random variable. It is also known as the Singh–Maddala distribution [ 3 ] and is one of a number of different distributions sometimes called the "generalized log ...
This distribution for a = 0, b = 1 and c = 0.5—the mode (i.e., the peak) is exactly in the middle of the interval—corresponds to the distribution of the mean of two standard uniform variables, that is, the distribution of X = (X 1 + X 2) / 2, where X 1, X 2 are two independent random variables with standard uniform distribution in [0, 1]. [1]
Count data can take values of 0, 1, 2, … (non-negative integer values). [2] Other examples of count data are the number of hits recorded by a Geiger counter in one minute, patient days in the hospital, goals scored in a soccer game, [3] and the number of episodes of hypoglycemia per year for a patient with diabetes. [4]
The function corresponding to the L 0 space is not a norm, and is thus often referred to in quotes: 0-"norm". In equations, for a given (finite) data set X, thought of as a vector x = (x 1,…,x n), the dispersion about a point c is the "distance" from x to the constant vector c = (c,…,c) in the p-norm (normalized by the number of points n):
Unlike the more commonly used Weibull distribution, it can have a non-monotonic hazard function: when >, the hazard function is unimodal (when ≤ 1, the hazard decreases monotonically). The fact that the cumulative distribution function can be written in closed form is particularly useful for analysis of survival data with censoring . [ 9 ]
For example, a distribution of points in the plane will typically have a mean and a mode, but the concept of median does not apply. The median makes sense when there is a linear order on the possible values. Generalizations of the concept of median to higher-dimensional spaces are the geometric median and the centerpoint.
Here x ≥ 0 means that each component of the vector x should be non-negative, and ‖·‖ 2 denotes the Euclidean norm. Non-negative least squares problems turn up as subproblems in matrix decomposition, e.g. in algorithms for PARAFAC [2] and non-negative matrix/tensor factorization. [3] [4] The latter can be considered a generalization of ...