Question

我有一维数据框作为输入：

A,1,B,2,C,3,D,4

我需要转换为这样的2D数据框：

A,1
B,2
C,3
D,4

我该怎么做？我无法使用matrix(...)，因为数据框包含非数字值。

根据要求[编辑] dput数据：

structure(list(V1 = structure(1L, .Label = "A", class = "factor"), 
V2 = 1, V3 = structure(1L, .Label = "B", class = "factor"), 
V4 = 2, V5 = structure(1L, .Label = "C", class = "factor"), 
V6 = 3, V7 = structure(1L, .Label = "D", class = "factor"), 
V8 = 4), .Names = c("V1", "V2", "V3", "V4", "V5", "V6", 
"V7", "V8"), class = "data.frame", row.names = c(NA, -1L))

Answer 1

您可以使用沿列回收的逻辑向量来对1D数据帧中的列进行子集化。

data.frame(x = unlist(d[ , c(TRUE, FALSE)]), y = unlist(d[ , c(FALSE, TRUE)]))
#    x y
# V1 A 1
# V3 B 2
# V5 C 3
# V7 D 4

Answer 2

matrix函数参数byrow在这里有帮助。然后你可以改变课程

data <- data.frame(matrix(c("A",1,"B",2,"C",3,"D",4),ncol=2,byrow=T))
class(data$X1) <- "numeric"

sapply(data,class)
       X1        X2 
"integer"  "factor"

Answer 3

> matrix( sapply(dat,as.character), 4, byrow=TRUE)
     [,1] [,2]
[1,] "A"  "1" 
[2,] "B"  "2" 
[3,] "C"  "3" 
[4,] "D"  "4"

如果我们可以假设＆＃34; n＆＃34;作为列号的请求是一个值的数值因子：

> matrix( sapply(dat,as.character), length(dat)/2, byrow=TRUE)
     [,1] [,2]
[1,] "A"  "1" 
[2,] "B"  "2" 
[3,] "C"  "3" 
[4,] "D"  "4"

显然，如果第二列需要为数字类，则需要将其强制转换为数据框，但是问题描述中没有任何内容表明应该是这样的。

R将1D数据帧转换为2D数据帧

3 个答案: