如何将矩阵与R中的向量相乘?
当我们将矩阵与向量相乘时,输出就是向量。假设我们有一个矩阵M和向量V,那么它们可以乘以M%*%V。要了解逐步乘法,我们可以将向量中的每个值与矩阵中的行值相乘,然后找出该乘法的总和。
例1
M1<-matrix(1:25,nrow=5)M1
输出结果
[,1] [,2] [,3] [,4] [,5][1,] 1 6 11 16 21
[2,] 2 7 12 17 22
[3,] 3 8 13 18 23
[4,] 4 9 14 19 24
[5,] 5 10 15 20 25
示例
V1<-1:5V1
[1] 1 2 3 4 5
M1%*%V1
输出结果
[,1][1,] 215
[2,] 230
[3,] 245
[4,] 260
[5,] 275
例2
M2<-matrix(1:100,nrow=10)M2
输出结果
[,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10][1,] 1 11 21 31 41 51 61 71 81 91
[2,] 2 12 22 32 42 52 62 72 82 92
[3,] 3 13 23 33 43 53 63 73 83 93
[4,] 4 14 24 34 44 54 64 74 84 94
[5,] 5 15 25 35 45 55 65 75 85 95
[6,] 6 16 26 36 46 56 66 76 86 96
[7,] 7 17 27 37 47 57 67 77 87 97
[8,] 8 18 28 38 48 58 68 78 88 98
[9,] 9 19 29 39 49 59 69 79 89 99
[10,] 10 20 30 40 50 60 70 80 90 100
示例
V2<-1:10V2
[1] 1 2 3 4 5 6 7 8 9 10
M2%*%V2
输出结果
[,1][1,] 3355
[2,] 3410
[3,] 3465
[4,] 3520
[5,] 3575
[6,] 3630
[7,] 3685
[8,] 3740
[9,] 3795
[10,] 3850
例子3
M3<-matrix(rnorm(36,5,1),nrow=18)M3
输出结果
[,1] [,2][1,] 3.627929 6.929146
[2,] 3.363237 4.400114
[3,] 4.640349 5.089977
[4,] 6.201115 5.483314
[5,] 4.354126 7.024478
[6,] 4.489391 6.631517
[7,] 4.400877 6.370375
[8,] 5.545603 2.586863
[9,] 4.508706 4.145658
[10,] 5.191536 5.562368
[11,] 4.441472 4.634800
[12,] 5.922700 4.657329
[13,] 6.153998 4.224459
[14,] 3.627590 4.987152
[15,] 6.290181 5.699693
[16,] 6.154902 5.031921
[17,] 6.445679 5.216649
[18,] 5.261013 5.407813
示例
V3<-c(5,10)V3
[1] 5 10
M3%*%V3
输出结果
[,1][1,] 87.43110
[2,] 60.81733
[3,] 74.10152
[4,] 85.83872
[5,] 92.01541
[6,] 88.76213
[7,] 85.70814
[8,] 53.59664
[9,] 64.00011
[10,] 81.58136
[11,] 68.55536
[12,] 76.18679
[13,] 73.01458
[14,] 68.00947
[15,] 88.44784
[16,] 81.09372
[17,] 84.39489
[18,] 80.38319
例子4
M4<-matrix(rpois(50,10),ncol=5)M4
输出结果
[,1] [,2] [,3] [,4] [,5][1,] 12 2 9 4 14
[2,] 13 12 10 5 13
[3,] 10 8 9 12 9
[4,] 11 9 9 10 11
[5,] 12 11 14 6 8
[6,] 12 5 13 8 13
[7,] 16 11 10 14 10
[8,] 12 11 13 12 6
[9,] 4 7 5 8 10
[10,] 9 14 10 13 15
示例
V4<-1:5V4
[1] 1 2 3 4 5
M4%*%V4
输出结果
[,1][1,] 129
[2,] 152
[3,] 146
[4,] 151
[5,] 140
[6,] 158
[7,] 174
[8,] 151
[9,] 115
[10,] 194
示例
M5<-matrix(sample(0:9,20,replace=TRUE),ncol=5)M5
输出结果
[,1] [,2] [,3] [,4] [,5][1,] 5 8 0 7 0
[2,] 9 9 7 8 0
[3,] 9 1 7 0 9
[4,] 6 6 5 7 6
示例
V5<-c(2,4,6,8,10)V5
[1] 2 4 6 8 10
M5%*%V5
输出结果
[,1][1,] 98
[2,] 160
[3,] 154
[4,] 182
以上是 如何将矩阵与R中的向量相乘? 的全部内容, 来源链接: utcz.com/z/353401.html