Note that the straightforward implementation of the boids algorithm has an asymptotic complexity of O(n 2 ). Each boid needs to consider each other boid, if only to determine if it is not a nearby flockmate. However it is possible to reduce this cost down to nearly O(n) by the use of a suitable spatial data structure which allows the boids to be kept sorted by their location. Finding the nearby flockmates of a given boid then requires examining only the portion of the flock which is within the general vicinity. Using such algorithmic speed-ups and modern fast hardware, large flocks can be simulated in real time, allowing for interactive applications . [new]
The Sacred Grove of Oshogbo was one place I had been looking forward to visiting in Nigeria. As prevalent as indigenous religions still are in West Africa, it is often hard to find public expressions of them in towns and cities; the Christianity brought by European slavers and colonialists has taken root and pushed most of these religions out of mainstream life. But in the Sacred Grove shrines honor all the local deities, including Obatala, the god of creation, Ogun, the god of iron, and Oshun, the goddess of water, whose aqueous essence is made manifest by the river running through the trees. The place is unique in the Yoruba religion, and that intrigued me.