Fastest way to zero out low values in array?

Question

So, lets say I have 100,000 float arrays with 100 elements each. I need the highest X number of values, BUT only if they are greater than Y. Any element not matching this

Answer 1

Use a heap.

This works in time O(n*lg(HighCountX)).

import heapq

heap = []
array =  [.06, .25, 0, .15, .5, 0, 0, 0.04, 0, 0]
highCountX = 3
lowValY = .1

for i in range(1,highCountX):
    heappush(heap, lowValY)
    heappop(heap)

for i in range( 0, len(array) - 1)
    if array[i] > heap[0]:
        heappush(heap, array[i])

min = heap[0]

array = [x if x >= min else 0 for x in array]

deletemin works in heap O(lg(k)) and insertion O(lg(k)) or O(1) depending on which heap type you use.