Method for creating an index for reporting large-scale variant clusterings

A computer-implemented method for computing an index for a first density-based clustering of a collection of records, wherein the index is stored with a storage device,

• wherein each record
• is initially marked as unprocessed,
• comprises a first attribute and a second attribute, and
• forms part of a neighborhood within a predefined threshold distance,
• wherein a record is a core record if its neighborhood comprises at least a predefined number of records, and the record is a non-core record if its neighborhood comprises less than the predefined number of records, wherein the index is computed according to the following steps:
• a) selecting, by one or more computer processors, an unprocessed record of the collection of records and computing a core distance for the selected unprocessed record, wherein the core distance is the smallest distance from the selected unprocessed record at which its neighborhood still comprises at least the predefined number of records,
• b) if the selected unprocessed record is a core record, assigning, by one or more computer processors, the core distance to the first attribute and labelling the selected unprocessed record as core-record, else, assigning a predefined value to the first attribute and labelling the selected unprocessed record as non-core record,
• c) adding, by one or more computer processors, the selected unprocessed record to the index and marking the selected unprocessed record as processed,
• d) if the selected processed record is a core record, processing, by one or more computer processors, each record of the neighborhood of the selected processed record by:
• computing, by one or more computer processors, a reachability distance for each record, wherein the reachability distance is the smallest distance at which a respective record is still directly density-reachable from the selected processed record,
• populating, by one or more computer processors, a priority queue with each record which is marked as unprocessed in an ascending order of its reachability distance, wherein the reachability distance is assigned to the second attribute,
• removing, by one or more computer processors, each record which was previously labelled as non-core record and outputs a smaller reachability distance than previously assigned to its second attribute from the index, wherein each removed record is marked as unprocessed and wherein each removed record is inserted into the priority queue according to the ascending order of its reachability distance, and
• e) appending, by one or more computer processors, each record of the priority queue to the index, wherein each record is marked, by one or more computer processors, as processed, wherein if the appended record is a core record, then the records of its neighborhood are processed according to step d),
• wherein the steps a) to e) are repeated until all records of the collection of records are processed and inserted into the index.