###############
# Authored by Weisheng Jiang
# Book 4  |  From Basic Arithmetic to Machine Learning
# Published and copyrighted by Tsinghua University Press
# Beijing, China, 2022
###############

# Bk4_Ch4_01.py

import numpy as np

# 2d matrix
A_matrix = np.matrix([[2,4],
                      [6,8]])
print(A_matrix.shape)
print(type(A_matrix))

# 1d array
A_1d = np.array([2,4])
print(A_1d.shape)
print(type(A_1d))

# 2d array
A_2d = np.array([[2,4],
                 [6,8]])
print(A_2d.shape)
print(type(A_2d))

# 3d array
A1 = [[2,4],
      [6,8]]

A2 = [[1,3],
      [5,7]]

A3 = [[1,0],
      [0,1]]
A_3d = np.array([A1,A2,A3])
print(A_3d.shape)
print(type(A_3d))