You can join all your arrays into a single big array with concatenate. >>> import numpy as np >>> a = np.concatenate(array_of_arrays)
Then count the number of occurrances of each unique element using this trick with searchsorted. This should be pretty fast. >>> a.sort() >>> unique_a = np.unique(a) >>> count = [] >>> for val in unique_a: ... count.append(a.searchsorted(val,side='right') - a.searchsorted(val, side='left')) >>> mostcommonvals = unique_a[np.argsort(count)[-25:]] Neil -- http://mail.python.org/mailman/listinfo/python-list
