Illustration of an isotropic range search using regular grids with different cell sizes. The points in panels a and b indicate a randomly generated dataset in 2D, with the current reference point marked in red. Yellow areas denote cells that are visited, given the query range indicated by red circles. Panels c and d show the arrangements of data points in memory for the column-major grid configurations in panels a and b, respectively. Pink regions indicate data points that are visited during the range search process. The cell sizes are chosen for illustration purposes and are not meant to be optimal.