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get the indexes of the top n elements in a numpy 2d-array
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import numpy as np | |
import bottleneck as bn | |
def top_n_indexes(arr, n): | |
idx = bn.argpartsort(arr, arr.size-n, axis=None)[-n:] | |
width = arr.shape[1] | |
return [divmod(i, width) for i in idx] | |
np.random.seed(47) | |
arr = np.random.rand(50, 50) | |
idx = top_n_indexes(arr, 8) | |
idx.sort(key = lambda tup: tup[0]) | |
print idx | |
# [(5, 45), (11, 8), (16, 14), (24, 40), (25, 35), (31, 7), (35, 6), (49, 43)] | |
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