Computing Order Statistics
The problem of computing the kth smallest (or largest) element of a list is called the selection problem and is solved by a selection algorithm. Although this problem is difficult for very large lists, sophisticated selection algorithms have been created that can solve this problem in time proportional to the number of elements in the list, even if the list is totally unordered. If the data is stored in certain specialized data structures, this time can be brought down to O(log n). In many applications all order statistics are required, in which case a sorting algorithm can be used and the time taken is O(n log n).
Read more about this topic: Order Statistic
Famous quotes containing the words order and/or statistics:
“In Russia there is an emigration of intelligence: émigrés cross the frontier in order to read and to write good books. But in doing so they contribute to making their fatherland, abandoned by spirit, into the gaping jaws of Asia that would like to swallow our little Europe.”
—Friedrich Nietzsche (18441900)
“We already have the statistics for the future: the growth percentages of pollution, overpopulation, desertification. The future is already in place.”
—Günther Grass (b. 1927)