numpy

1. np.argsort 数据排序 对应的下标

import numpy as np

scores = np.array([0.9, 0.5, 0.3, 0.6])

print(scores.argsort())  # 从小到大排序 对应原数的index
print(scores.argsort()[::-1]) # 逆序 从大到小

[2 1 3 0]
[0 3 1 2]

2. np.tile 矩阵 平移复制

import numpy as np

a = np.array([0, 1, 2])
print(a)  # [0 1 2]
print(a.shape)  # (3,)

a1 = np.tile(a, 2)
print(a1)  # [0 1 2 0 1 2]
print(a1.shape)  # (6,)

a2 = np.tile(a, (2, 3))
print(a2)
print(a2.shape)  # (2, 9)
#  [[0 1 2 0 1 2 0 1 2]
#  [0 1 2 0 1 2 0 1 2]]