zoukankan      html  css  js  c++  java
  • A convenient way to recognize and handwrite multidimensional arrays in Numpy

    As a new learner of Numpy, it is very common to be confused by the form of array, braces nested in braces, such as ‘a= np.array[[[1],[2],[3]]]’ so that its shape cannot be precisely known by the users, although the shape can be fetched through ‘a.shape’, making users unable to perform multidimensional array correctly.

    The method is as the following:(1)every array needs a most out brace.(2) Go inner, the number of paired brace is the element number of 0 axis, 1 axis, 2 axis etc.(3) The dimension number increased along with the going-inner, until the number element is reached, the sum of levels is the dimensional number.

    For example:

    >>> import numpy as np
    >>> data=np.arange(4)
    >>> data1=data.reshape((4,1))
    >>> data2=data.reshape((1,4))
    >>> data3=data.reshape((2,2))
    >>> data4=data.reshape((1,2,2))
    >>> data5=data.reshape((2,1,2))
    >>> data6=data.reshape((2,2,1))
    >>> data
    array([0, 1, 2, 3])
    >>> data1
    array([[0],
           [1],
           [2],
           [3]])
    >>> data2
    array([[0, 1, 2, 3]])
    >>> data3
    array([[0, 1],
           [2, 3]])
    >>> data4
    array([[[0, 1],
            [2, 3]]])
    >>> data5
    array([[[0, 1]],
    
           [[2, 3]]])
    >>> data6
    array([[[0],
            [1]],
    
           [[2],
            [3]]])

    ①data1's shape is (4,1),so firstly, the most out brace pair shall be set-->[ ], and then 0 axis is 4, meaning 4 pairs of brace inside -->[ [ ],[ ],[ ],[ ] ] ,finally, 1 axis is 1,and is the final dimension, meaning 1 number element shall be inside-->[ [0],[1],[2],[3]].

    ② data2's shape is (1,4), firstly-->[ ], then -->[ [ ] ], finally -->[ [ 0,1,2,3] ]

    ③ data3's shape is (2,2), firstly-->[ ] ,then--> [ [ ], [ ] ], finally-->[ [0,1], [2,3] ]

    ④data4' shape is (1,2,2), firstly-->[ ] ,then-->[ [ ] ], then--> [ [ [ ], [ ] ] ], finally--> [ [ [ 0,1], [2,3 ] ] ]

    ⑤data5's shape is (2,1,2),firstly--> [ ],then-->[ [ ],[ ] ], then-->[ [ [ ] ], [ [ ] ] ], finally --> [ [ [ 0,1],[ [ 2,3] ] ]

    ⑥data6's shape is (2,2,1),firstly-->[ ],then --> [ [ ] ,[ ] ],then-->[ [ [ ], [ ] ], [ [ ] , [ ] ] ],finally-->[ [ [ 0],[1] ], [ [2],[3] ] ]

    ##### 愿你一寸一寸地攻城略地,一点一点地焕然一新 #####
  • 相关阅读:
    安卓SQLite数据库操作(上)
    Android 查看设备信息
    Unity 编辑器学习(四)之 静态游戏物体
    Unity 编辑器学习(三)之 Light & Baked
    Unity 编辑器学习(二)之 全局光照(GI)
    unity 自动删除未引用的Assets下的资源
    C# http服务器
    unity 美术注意事项
    软件版本号命名规范
    Unity 框架(一)
  • 原文地址:https://www.cnblogs.com/johnyang/p/11819433.html
Copyright © 2011-2022 走看看