JDR quality for different running times of HappieClust. HappieClust JDR quality and running time for data=Shyamsundar05, s = 0.5, q = 20. HappieClust running times for 106 and 107 distances are 6 and 50 seconds, respectively. The time for full AHC is 145 seconds with EPCLUST 1.0 (marked with a triangle) and 612 seconds with HappieClust. This 4-fold difference is due to the overhead in HappieClust used for working with incomplete information.