\[{H^{(2)}_{\nu}}\left(z\right)=i\csc\left(\nu\pi\right)\left(J_{-\nu}\left(z%
\right)-e^{\nu\pi i}J_{\nu}\left(z\right)\right)=\csc\left(\nu\pi\right)\left(%
Y_{-\nu}\left(z\right)-e^{\nu\pi i}Y_{\nu}\left(z\right)\right).\]