将多列堆叠成单列，在R中具有单个值

Question

ID Time  U1 U2 U3 U4
1  20     1  0  0  0 
2  20     0  1  0  0
3  20     0  0  1  0 
4  20     0  0  0  1

我需要保持这样的状态：

ID Time   U 
1  20    U1 
2  20    U2 
3  20    U3 
4  20    U4

我试过：

X_D <- as.data.frame(X)
X_new <- stack(X_D, select = -c(ID, Time))

Answer 1

尝试

library(dplyr)
df <- data.frame(ID = 1:4, Time = 20, U1 = c(1,0,0,0), U2 = c(0,1,0,0), U3 = c(0,0,1,0), U4 = c(0,0,0,1))

df %>% pivot_longer(cols = 3:6, names_to = "U") %>% 
  filter(value == 1) %>% 
  select(-value)

将多列堆叠成单列，在R中具有单个值

stacking multiple columns into single column with single value in R

r

dplyr

stack

melt