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The following are among the properties of log-concave distributions: If a density is log-concave, so is its cumulative distribution function (CDF). If a multivariate density is log-concave, so is the marginal density over any subset of variables. The sum of two independent log-concave random variables is log-concave. This follows from the fact ...
The Brunn–Minkowski inequality asserts that the Lebesgue measure is log-concave. The restriction of the Lebesgue measure to any convex set is also log-concave.. By a theorem of Borell, [2] a probability measure on R^d is log-concave if and only if it has a density with respect to the Lebesgue measure on some affine hyperplane, and this density is a logarithmically concave function.
This is the source of the log-concave restriction: if a distribution is log-concave, then its logarithm is concave (shaped like an upside-down U), meaning that a line segment tangent to the curve will always pass over the curve. If not working in log space, a piecewise linear density function can also be sampled via triangle distributions [8]
Its density has two inflection points (where the second derivative of is zero and changes sign), located one standard deviation away from the mean, namely at = and = +. [22] Its density is log-concave .
An important example of a log-concave density is a function constant inside a given convex body and vanishing outside; it corresponds to the uniform distribution on the convex body, which explains the term "central limit theorem for convex bodies".
Every distribution with log-concave density is a maximal entropy distribution with specified mean μ and deviation risk measure D . [10] In particular, the maximal entropy distribution with specified mean and deviation is:
Ed Martin, President Donald Trump's top federal prosecutor in Washington, announced on Friday he has launched an investigation into government employees accused of stealing property and making ...
In probability theory and statistics, the log-Laplace distribution is the probability distribution of a random variable whose logarithm has a Laplace distribution. If X has a Laplace distribution with parameters μ and b, then Y = e X has a log-Laplace distribution. The distributional properties can be derived from the Laplace distribution.