R构造列值的摘要

Question

我想制作一个数组，用包含在所述行中的唯一值来汇总数据框的行。

使用以下示例代码：

ref <- c(1:8)

data1 <- c("A","","C","","","","A","")
data2 <- c("A","","","A","C","","","")
data3 <- c("","B","","","","","","B")
data4 <- c("A","B","","","","D","A","")

initial.data <- data.frame(ref, data1, data2, data3, data4)

我可以得到我想要的：

summary.data <- paste(initial.data[,2], initial.data[,3], 
                  initial.data[,4], initial.data[,5], sep='') 

desired.data <- substring(summary.data,1,1)

但是，我想要一种更简洁的编码方式，并且不假定每一行只能取一个值。

Answer 1

你可以试试

 apply(initial.data[-1],1, function(x) unique(x[x!='']))
 #[1] "A" "B" "C" "A" "C" "D" "A" "B"

或者

 substr(do.call(paste0, initial.data[-1]),1,1)
 #[1] "A" "B" "C" "A" "C" "D" "A" "B"

或使用max.col

 initial.data[cbind(1:nrow(initial.data),max.col(initial.data[-1]!='')+1)]
 #[1] "A" "B" "C" "A" "C" "D" "A" "B"

R构造列值的摘要

R construct summary of values from columns

r

unique

dataframe