矩阵-向量运算

R 数据科学的线性代数

Eric Eager

Data Scientist at Pro Football Focus

矩阵与向量乘法的原理

print(A)

     [,1] [,2]
[1,]    1   -1
[2,]    2    1
[3,]    4   -2

print(b)

1 2

A%*%b

     [,1]
[1,]   -1
[2,]    4
[3,]    0

A[1,]%*%b

     [,1]
[1,]    7

A[2,]%*%b

     [,1]
[1,]    9

A%*%b

     [,1]
[1,]    7
[2,]    9

R 数据科学的线性代数