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import numpy as np

# 行列配列を作成
record = np.array([[1, 2], [3, 4]])
print(record)
#[[1 2]
# [3 4]]

# 0-9までのrange作成
record_b = np.array(np.arange(10))
print(record_b)
# [0 1 2 3 4 5 6 7 8 9]

# 2*5に分割
record_c = record_b.reshape(2, 5)
print(record_c)
#[[0 1 2 3 4]
# [5 6 7 8 9]]

r_1 = np.arange(4).reshape(2,2)
r_2 = np.arange(3,7).reshape(2,2)

# 行列同士の和
print(r_1 + r_2)

# r_1の行列を入れ替えての和
print(r_1.T + r_2)

# 行列の積 @see https://ja.wikipedia.org/wiki/%E8%A1%8C%E5%88%97%E3%81%AE%E4%B9%97%E6%B3%95
print(np.dot(r_1, r_2))

# ベクトル計算
v = np.array([10, 20])
# array([10, 20])
np.dot(r_1,v)
# array([20, 80])
np.dot(v,r_1)
# array([40, 70])