Notation |
![\textrm{GEV}(\mu,\,\sigma,\,\xi)](https://wikimedia.org/api/rest_v1/media/math/render/svg/75afb1aca6c44e6d6d0201667db097defb368008) |
Parameters |
μ ∈ R — location, σ > 0 — scale, ξ ∈ R — shape. |
Support |
x ∈ [ μ − σ / ξ, +∞) when ξ > 0, x ∈ (−∞, +∞) when ξ = 0, x ∈ (−∞, μ − σ / ξ ] when ξ < 0. |
PDF |
where
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CDF |
for x ∈ support |
Mean |
![\begin{cases}\mu + \sigma\frac{\Gamma(1-\xi)-1}{\xi} & \text{if}\ \xi\neq 0,\xi<1,\\ \mu + \sigma\,\gamma & \text{if}\ \xi=0,\\ \infty & \text{if}\ \xi\geq 1,\end{cases}](https://wikimedia.org/api/rest_v1/media/math/render/svg/57c7e8e098790a3382fe8706d10b596991b7f501)
where is Euler’s constant. |
Median |
![\begin{cases}\mu + \sigma \frac{(\ln2)^{-\xi}-1}{\xi} & \text{if}\ \xi\neq0,\\ \mu - \sigma \ln\ln2 & \text{if}\ \xi=0.\end{cases}](https://wikimedia.org/api/rest_v1/media/math/render/svg/905eeae3856515ddf9c230d31b0b730c183067e5) |
Mode |
![\begin{cases}\mu + \sigma \frac{(1+\xi)^{-\xi}-1}{\xi} & \text{if}\ \xi\neq0,\\ \mu & \text{if}\ \xi=0.\end{cases}](https://wikimedia.org/api/rest_v1/media/math/render/svg/14cf4f5dd1b197a520983d167d1cfa3fae4af67c) |
Variance |
![\begin{cases}\sigma^2\,(g_2-g_1^2)/\xi^2 & \text{if}\ \xi\neq0,\xi<\frac12,\\ \sigma^2\,\frac{\pi^2}{6} & \text{if}\ \xi=0, \\ \infty & \text{if}\ \xi\geq\frac12,\end{cases}](https://wikimedia.org/api/rest_v1/media/math/render/svg/a69690f4f618458f9d99c5bbffaef10dcf4d42b5)
where gk = Γ(1 − kξ). |
Skewness |
![\begin{cases}\frac{g_3-3g_1g_2+2g_1^3}{(g_2-g_1^2)^{3/2}} & \text{if}\ \xi >0,\\ -\frac{g_3-3g_1g_2+2g_1^3}{(g_2-g_1^2)^{3/2}} & \text{if}\ \xi <0,\\ \frac{12 \sqrt{6} \zeta(3)}{\pi^3} & \text{if}\ \xi=0.\end{cases}](https://wikimedia.org/api/rest_v1/media/math/render/svg/c7c2ccb19ee60aa8a44a25c4143dd6753145828b)
where is Riemann zeta function
|
Ex. kurtosis |
![\begin{cases}\frac{g_4-4g_1g_3+6g_2g_1^2-3g_1^4}{(g_2-g_1^2)^{2}}-3 & \text{if}\ \xi\neq0,\xi<\frac{1}{4},\\ \frac{12}{5} & \text{if}\ \xi=0,\\ \infty & \text{if}\ \xi\ge\frac{1}{4}.\end{cases}](https://wikimedia.org/api/rest_v1/media/math/render/svg/965531a9e58009c0a98ad7bd0fbb252439b2c173) |
Entropy |
![\log(\sigma)\,+\,\gamma\xi\,+\,(\gamma+1)](https://wikimedia.org/api/rest_v1/media/math/render/svg/54313319ad352a34769d26f9a0181aeb0914112d) |
MGF |
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CF |
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