Abstract: GriSPy (Grid Search in Python) uses a regular grid search algorithm for quick fixed-radius nearest-neighbor lookup. It indexes a set of k-dimensional points in a regular grid providing a fast approach for nearest neighbors queries. Optional periodic boundary conditions can be provided for each axis individually. GriSPy implements three types of queries: <i>bubble</i>, <i>shell</i> and the <i>nth-nearest</i>, and offers three different metrics of interest in astronomy: the <i>Euclidean</i> and two distance functions in spherical coordinates of varying precision, <i>haversine</i> and <i>Vincenty</i>. It also provides a custom distance function. GriSPy is particularly useful for large datasets where a brute-force search is not practical.
Credit: Chalela, Martín; Sillero, Emanuel; Pereyra, Luis; Garcia, Mario A.; Cabral, Juan B.; Lares, Marcelo; Merchán, Manuel
Preferred citation method: https://ui.adsabs.harvard.edu/abs/2019arXiv191209585C