Ordering points to identify the clustering structure (OPTICS) is an algorithm for finding density-based clusters in spatial data. Its basic idea is similar to DBSCAN, but it addresses one of DBSCAN's major weaknesses: the problem of detecting meaningful clusters in data of varying density. In order to do so, the points of the database are (linearly) ordered such that points which are spatially closest become neighbors in the ordering. This implementation is part of the M-Atlas Package.