Statistics 简明教程
Statistics - Gamma Distribution
伽马分布表示两参数族的连续概率分布。伽马分布通常由三种参数组合设计。
The gamma distribution represents continuous probability distributions of two-parameter family. Gamma distributions are devised with generally three kind of parameter combinations.
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A shape parameter $ k $ and a scale parameter $ \theta $.
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A shape parameter $ \alpha = k $ and an inverse scale parameter $ \beta = \frac{1}{ \theta} $, called as rate parameter.
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A shape parameter $ k $ and a mean parameter $ \mu = \frac{k}{\beta} $.

每个参数都是正实数。Gamma 分配是由以下标准驱动的最大熵概率分配。
Each parameter is a positive real numbers. The gamma distribution is the maximum entropy probability distribution driven by following criteria.
Formula
其中——
Where −
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${\alpha}$ = location parameter.
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${\beta}$ = scale parameter.
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${x}$ = random variable.
Formula
其中——
Where −
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${\alpha}$ = location parameter.
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${\beta}$ = scale parameter.
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${x}$ = random variable.
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${\gamma(\alpha, \beta x)} $ = lower incomplete gamma function.