包络柯西分布

有一个形状参数 \(c\in\left(0,1\right)\) 在有支持的情况下 \(x\in\left[0,2\pi\right]\)

\BEGIN{eqnarray*}f\Left(x;c\right)&=&\frac{1-c^{2}}{2\pi\Left(1+c^{2}-2c\cos x\right)}\\ G_{c}\Left(x\Right)&=&\frac{1}{\pi}\arctan\left(\frac{1+c}{1-c}\tan\left(\frac{x}{2}\right)\right)\\ R_{c}\Left(Q\Right)&=&2\arctan\Left(\frac{1-c}{1+c}\tan\Left(\pi Q\Right)\Right)\\ f\Left(x;c\Right)&=&\Left\{ \BEGIN{array}{ccc} G_{c}\Left(x\Right)&&0\leq x<\pi\\ 1-g_{c}\Left(2\pi-x\right)&&\pi\leq x\leq2\pi \end{数组} \对。\\ g\Left(q;c\Right)&=&\Left\{ \BEGIN{array}{ccc} R_{c}\Left(Q\Right)&&0\leq Q<\frac{1}{2}\\ 2\pi-r_{c}\Left(1-q\right)&&\frac{1}{2}\leq q\leq1 \end{数组} \对。\end{eqnarray*}
\[H\Left [X\right] =\log\Left(2\pi\Left(1-c^{2}\Right)\Right)。\]

实施: scipy.stats.wrapcauchy