R语言,如何根据row的index提取矩阵?谢谢指导!

已知1.targetmatrix <- matrix(1:100, nrow = 20),2.targetindex <- c(2, 8, 12, 15, 19)
[,1] [,2] [,3] [,4] [,5]
[1,] 1 21 41 61 81
[2,] 2 22 42 62 82
[3,] 3 23 43 63 83
[4,] 4 24 44 64 84
[5,] 5 25 45 65 85
[6,] 6 26 46 66 86
[7,] 7 27 47 67 87
[8,] 8 28 48 68 88
[9,] 9 29 49 69 89
[10,] 10 30 50 70 90
[11,] 11 31 51 71 91
[12,] 12 32 52 72 92
[13,] 13 33 53 73 93
[14,] 14 34 54 74 94
[15,] 15 35 55 75 95
[16,] 16 36 56 76 96
[17,] 17 37 57 77 97
[18,] 18 38 58 78 98
[19,] 19 39 59 79 99
[20,] 20 40 60 80 100
想得到两个新矩阵——
1.根据条件2从矩阵中提取对应行,并构成新矩阵
2.另一个新矩阵恰好不包含条件2中的那些行索引
(可不可以附一下下代码。。。)
我查后,尝试了这样,targetmatrix[rbind(1:nrow(targetmatrix), targetindex)],也不行。。。

1个回答

#1.得到对应index的行
 targetmatrix[targetindex,]
#2.除去对应index的行 
 targetmatrix[-targetindex,]
G_mumuxi
G木木夕 OK了,多谢!
大约 4 年之前 回复
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