如何通过定义列数将向量转换为R中的数据帧？

如果我们有一个向量，其中替代值可以创建表格形式，那么我们可能希望将向量转换为数据帧。为此，我们首先需要将向量转换为具有适当列数/行数的矩阵，然后使用as.data.frame函数将其作为数据帧读取。查看以下示例以了解其工作原理。

例1

> x1<-c(rep(c(1,"male"),times=10),rep(c(2,"female"),times=10))
> x1

输出结果

[1] "1" "male" "1" "male" "1" "male" "1" "male"
[9] "1" "male" "1" "male" "1" "male" "1" "male"
[17] "1" "male" "1" "male" "2" "female" "2" "female"
[25] "2" "female" "2" "female" "2" "female" "2" "female"
[33] "2" "female" "2" "female" "2" "female" "2" "female"

将x1转换为数据帧-

> x1_df<-as.data.frame(matrix(x1,ncol=2,byrow=TRUE))
> x1_df

输出结果

   V1   V2
1  1   male
2  1   male
3  1   male
4  1   male
5  1   male
6  1   male
7  1   male
8  1   male
9  1   male
10 1   male
11 2 female
12 2 female
13 2 female
14 2 female
15 2 female
16 2 female
17 2 female
18 2 female
19 2 female
20 2 female

例2

将x2转换为数据帧-

> x2<-c(rep(c("Grp1",rpois(1,1)),times=10),rep(c("Grp2",rpois(1,8)),times=10))
> x2

输出结果

[1] "Grp1" "5" "Grp1" "5" "Grp1" "5" "Grp1" "5" "Grp1" "5"
[11] "Grp1" "5" "Grp1" "5" "Grp1" "5" "Grp1" "5" "Grp1" "5"
[21] "Grp2" "11" "Grp2" "11" "Grp2" "11" "Grp2" "11" "Grp2" "11"
[31] "Grp2" "11" "Grp2" "11" "Grp2" "11" "Grp2" "11" "Grp2" "11"

例2

> x2_df<-as.data.frame(matrix(x2,ncol=2,byrow=TRUE))
> x2_df

输出结果

    V1  V2
1  Grp1 5
2  Grp1 5
3  Grp1 5
4  Grp1 5
5  Grp1 5
6  Grp1 5
7  Grp1 5
8  Grp1 5
9  Grp1 5
10 Grp1 5
11 Grp2 11
12 Grp2 11
13 Grp2 11
14 Grp2 11
15 Grp2 11
16 Grp2 11
17 Grp2 11
18 Grp2 11
19 Grp2 11
20 Grp2 11

范例3

将x3转换为数据帧-

> x3<-c(rep(c("Grp1",rnorm(1),rpois(1,10)),times=10),rep(c("Grp2",rnorm(1),rpois(1,2)),times=10))
> x3

输出结果

[1] "Grp1" "0.756362500132569" "4"
[4] "Grp1" "0.756362500132569" "4"
[7] "Grp1" "0.756362500132569" "4"
[10] "Grp1" "0.756362500132569" "4"
[13] "Grp1" "0.756362500132569" "4"
[16] "Grp1" "0.756362500132569" "4"
[19] "Grp1" "0.756362500132569" "4"
[22] "Grp1" "0.756362500132569" "4"
[25] "Grp1" "0.756362500132569" "4"
[28] "Grp1" "0.756362500132569" "4"
[31] "Grp2" "-0.339861988439845" "1"
[34] "Grp2" "-0.339861988439845" "1"
[37] "Grp2" "-0.339861988439845" "1"
[40] "Grp2" "-0.339861988439845" "1"
[43] "Grp2" "-0.339861988439845" "1"
[46] "Grp2" "-0.339861988439845" "1"
[49] "Grp2" "-0.339861988439845" "1"
[52] "Grp2" "-0.339861988439845" "1"
[55] "Grp2" "-0.339861988439845" "1"
[58] "Grp2" "-0.339861988439845" "1"

例子4

> x3_df<-as.data.frame(matrix(x3,ncol=3,byrow=TRUE))
> x3_df

输出结果

    V1          V2         V3
1  Grp1  0.756362500132569  4
2  Grp1  0.756362500132569  4
3  Grp1  0.756362500132569  4
4  Grp1  0.756362500132569  4
5  Grp1  0.756362500132569  4
6  Grp1  0.756362500132569  4
7  Grp1  0.756362500132569  4
8  Grp1  0.756362500132569  4
9  Grp1  0.756362500132569  4
10 Grp1  0.756362500132569  4
11 Grp2 -0.339861988439845  1
12 Grp2 -0.339861988439845  1
13 Grp2 -0.339861988439845  1
14 Grp2 -0.339861988439845  1
15 Grp2 -0.339861988439845  1
16 Grp2 -0.339861988439845  1
17 Grp2 -0.339861988439845  1
18 Grp2 -0.339861988439845  1
19 Grp2 -0.339861988439845  1
20 Grp2 -0.339861988439845  1