将单元格转换为 colnames

Question

这是我的数据框的例子：

> df
n   b    c    d
A Eeee Aaaa     
B Aaaa Bbbb Jjjj
C Jjjj Cccc     
D Aaaa Dddd

我想将单元格的值转换为唯一的列名，并用二进制值填充数据框，因此生成的数据框如下所示：

> resulting_df
n   Aaaa Bbbb Cccc Eeee Jjjj
A    1    0    0    1    0
B    1    1    0    0    1
C    0    0    1    0    1
D    0    0    0    0    0

我确定应该有一种无需循环即可完成此操作的简单方法。请帮忙

Answer 1

reshape2 可以做到：
数据：

df=structure(list(n = structure(1:4, .Label = c("A", "B", "C", "D"
), class = "factor"), b = structure(c(2L, 1L, 3L, 1L), .Label = c("Aaaa", 
"Eeee", "Jjjj"), class = "factor"), c = structure(1:4, .Label = c("Aaaa", 
"Bbbb", "Cccc", "Dddd"), class = "factor"), d = structure(c(NA, 
1L, NA, NA), .Label = "Jjjj", class = "factor")), .Names = c("n", 
"b", "c", "d"), class = "data.frame", row.names = c(NA, -4L))

library(reshape2)
dcast(melt(df,id.vars = "n"),n ~value,fun.aggregate = length)

给出：

  n Aaaa Bbbb Cccc Dddd Eeee Jjjj NA
1 A    1    0    0    0    1    0  1
2 B    1    1    0    0    0    1  0
3 C    0    0    1    0    0    1  1
4 D    1    0    0    1    0    0  1

然后您可以取消选择最后一列。

想法是将数据 melt() 成长格式，然后根据需要用 dcast() 重铸。
fun.aggregate=length用于填充数据框的值对应于出现的次数。

将单元格转换为 colnames

Converting cells into colnames

r

dataframe

reshape2