Numpy Slicing 주의점, Copy, boolean 연산
Slicing 할때, 주의할 점!!!!¶ In [329]: X[ 0:1+1 , 0:2+1] Out[329]: array([[84, 41, 74], [77, 92, 40]]) In [330]: Y = X[ 0:1+1 , 0:2+1] In [331]: Y Out[331]: array([[84, 41, 74], [77, 92, 40]]) In [332]: Y[0,0] = 100 In [333]: Y Out[333]: array([[100, 41, 74], [ 77, 92, 40]]) In [334]: X Out[334]: array([[100, 41, 74, 55, 32], [ 77, 92, 40, 91, 26], [ 52, 7, 46, 13, 50], [ 67, 76, 86, 70, 100]]) In [33..
2022. 11. 23.
Numpy 인덱스접근, 슬라이싱
In [223]: # X 에, 70보다 큰 데이터는 몇개인가? In [224]: X Out[224]: array([[84, 41, 74, 55, 32], [77, 92, 40, 91, 26], [52, 7, 46, 13, 50], [67, 76, 86, 70, 65]]) In [233]: X > 70 Out[233]: array([[ True, False, True, False, False], [ True, True, False, True, False], [False, False, False, False, False], [False, True, True, False, False]]) In [234]: (X > 70).sum() # True = 1 False = 0 이므로. Out[234]: 7 In [2..
2022. 11. 23.