On 4/26/07, * Anton Sherwood* <firstname.lastname@example.org <mailto:email@example.com>> wrote: All I really need is the four highest eigenvalues and their vectors. I'll have a look in "Python Cookbook" to see if there's a more efficient way to do that partial sort.
Maybe "heapq.nlargest ()" is what you want? http://www.python.org/doc/2.4/lib/module-heapq.html
Just doing argsort() on the whole array is faster (up until about 1e6 elements) because it does everything in C whereas heapq will create a lot of Python objects because it is treating the array as a general Python container.