1.判断array中数组元素的关系:
vector = np.array([5, 10, 15, 20])
vector == 10
array([False, True, False, False])
2.返回具体的值:
vector = np.array([5, 10, 15, 20])
equal_to_ten = (vector == 10)
print (equal_to_ten)
print(vector[equal_to_ten])
可以看到equal就是对应得索引,直接输出就可以vector[equal].
3.返回具体某一列符合条件的索引:
matrix = np.array([
[5, 10, 15],
[20, 25, 30],
[35, 40, 45]
])
# print(matrix[:,1])
second_column_25 = (matrix[:,1] == 25)|(matrix[:,1] == 10)
print (second_column_25)
print(matrix[second_column_25, :])
[ True True False]
[[ 5 10 15]
[20 25 30]]