Mercury (planet) at a steep angle. Mercury is 10° above the horizon when the planet appears directly above the Sun (i.e. its orbit appears vertical) and is at maximum elongation from the Sun (28°) and also when the Sun is 18° below the horizon, so the sky is just completely dark. This angle is the maximum altitude at which Mercury is visible in a completely dark sky. At middle latitudes, Mercury is more often and easily visible from the Southern Hemisphere than from the Northern. This is because Mercury's maximum western elongation occurs only during early autumn in the Southern Hemisphere, whereas
Nearest neighbor search clustering. The database is clustered and the most "promising" clusters are retrieved. Huge gains over VA-File, tree-based indexes and sequential scan have been observed. Also note the parallels between clustering and LSH. There are numerous variants of the NNS problem and the two most well-known are the "k"-nearest neighbor search and the ε-approximate nearest neighbor search. "k"-nearest neighbor search identifies the top "k" nearest neighbors to the query. This technique is commonly used in predictive analytics to estimate or classify a point based on the consensus of its neighbors. "k"-nearest neighbor graphs are graphs in which every point is connected