]> $$\text{sph\_legendre}\left(l,m,\theta \right)=Y_l^m\left(\theta ,0\right)={\left(-1\right)}^m\sqrt{\frac{2l+1}{4\pi }\frac{\left(l-m\right)!}{\left(l+m\right)!}}{P}_l^m\left(\cos \theta \right)$$