双重威布尔分布

这是威布尔分布的签名形式。有一个形状参数 \(c>0\) 。支持是 \(x\in\mathbb{{R}}\)

\Begin{eqnarray*}f\Left(x;c\Right)&=&\frac{c}{2}\left|x\right|^{c-1}\exp\left(-\left|x\right|^{c}\right)\\ f\Left(x;c\Right)&=&\Left\{ \BEGIN{array}{ccc} \frac{1}{2}\exp\left(-\left|x\right|^{c}\right)&&x\leq0\\ 1-\frac{1}{2}\exp\left(-\left|x\right|^{c}\right)&&x>0 \end{数组} \对。\\ g\Left(q;c\Right)&=&\Left\{ \BEGIN{array}{ccc} -\log^{1/c}\Left(\frac{1}{2q}\right)&&q\leq\frac{1}{2}\\ \log^{1/c}\Left(\frac{1}{2q-1}\right)&&q>\frac{1}{2} \end{数组} \对。\end{eqnarray*}
\[\begin{split}\MU_{n}^{\Prime}=\MU_{n}=\开始{案例} \Gamma\Left(1+\frac{n}{c}\Right)&n\text{Even}\\ 0&n\text{ODD} \结束{案例}\end{split}\]
\BEGIN{eqnarray*}m_{n}=\m&=&0\\ \MU_{2}&=&\Gamma\Left(\frac{c+2}{c}\Right)\\ \Gamma_{1}&=&0\\ \Gamma_{2}&=&\frac{\Gamma\left(1+\frac{4}{c}\right)}{\Gamma^{2}\left(1+\frac{2}{c}\right)}\\ m_{d}&=&\text{na双峰}\end{eqnarray*}

实施: scipy.stats.dweibull