p_{i,j+1}^{i}=(\frac{\Delta z D}{\Delta\theta^2}-\frac{\Delta z D}{2\Delta\theta\theta_{i,j}})p_{i-1,j}^{i} + (1-\frac{2\Delta z D}{\Delta\theta^2}-\Delta zA\theta_{i,j}^2)p_{i,j}^{i} + (\frac{\Delta z D}{2\Delta\theta\theta_{i,j}}+\frac{\Delta z D}{\Delta\theta^2})p_{i+1,j}^{i}-\omega\frac{n}{2c}\Delta z\theta_{i,j}^2} p_{i,j}^{r}