
154 STATISTICAL LEARNING AND DATA SCIENCE
trajectories that is a three- way extension is also NP-hard and no guarantee to find the
optimal s olution is available. There fore, to increase the chance to find the optimal solution
a multistart procedure is applied that consists of star ting the algorithm fr om different
random solutions and retaining the best solution.
13.6 Application
Cancer mortality data, initially from 122 countries, were extracted from the World Health
Organization statistical database (WHOSIS) in March 2005. This database contains abso-
lute numbers of deaths officially reported by WHO member states for the years 1980–2000.
For these