【1.3】Numpy學習-陣列轉置和形狀(.T/reshape()/resize())
阿新 • • 發佈:2019-01-04
Numpy學習-陣列轉置和形狀
import numpy as np ar1 = np.arange(10) ar2 = np.ones((5,2)) print(ar1,'\n',ar1.T) print(ar2,'\n',ar2.T) # .T方法:轉置,一維陣列轉置後結果不變 print('--------------------------------------------------') ar3 = ar1.reshape(2,5) # 用法一:直接將已有陣列改變形狀 ar4 = np.zeros((4,6)).reshape(3,8) # 用法二:生成陣列後直接改變形狀 ar5 = np.reshape(np.arange(12),(3,4)) # 用法三:引數內新增陣列,目標形狀 print(ar1,'\n',ar3) print(ar4) print(ar5) print('---------------------------------------') ar6 = np.resize(np.arange(5),(3,4)) print(ar6) # numpy.resize(a,new_shape):返回具有指定形狀的新陣列,如有必要可重複填充所需要的元素
結果如下:
[0 1 2 3 4 5 6 7 8 9] [0 1 2 3 4 5 6 7 8 9] [[1. 1.] [1. 1.] [1. 1.] [1. 1.] [1. 1.]] [[1. 1. 1. 1. 1.] [1. 1. 1. 1. 1.]] -------------------------------------------------- [0 1 2 3 4 5 6 7 8 9] [[0 1 2 3 4] [5 6 7 8 9]] [[0. 0. 0. 0. 0. 0. 0. 0.] [0. 0. 0. 0. 0. 0. 0. 0.] [0. 0. 0. 0. 0. 0. 0. 0.]] [[ 0 1 2 3] [ 4 5 6 7] [ 8 9 10 11]] --------------------------------------- [[0 1 2 3] [4 0 1 2] [3 4 0 1]]