How do you create categorical variables using dummy variables in r?

Question

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case1: 0, 0, 0, 0, 1, 1, 1, 1, 0, 0

case2: 1, 1, 0, 0, 1, 0, 0, 0, 1, 0

case3: 0, 1, 0, 0, 0, 1, 1, 0, 0, 1

I would like to get the following vectors from the table above.

answer: 2, mix, 0, 0, mix, mix, mix, 1, 2, 3

How do I solve the above problem in r?

Answer 1

I made my own function to solve the above problem.

I hope it helps people who have the same problems as me.

dummy_to_cate <- function(mydata,column_area){
  result_vec <- NA
  vec_q=NA
  colname <- colnames(mydata)
  
  result_vec[is.na(mydata[,column_area[1]])==FALSE]<-paste(colname[1])
  for (i in column_area[-1]) {
    vec_q[is.na(mydata[,column_area[i]])==FALSE] <-1
    vec_q[is.na(mydata[,column_area[i]])==TRUE] <-0
    result_vec[vec_q==1 & is.na(mydata[,column_area[1]])==TRUE]<- paste(colname[i])
  }
   df<-is.na(mydata[,column_area])==FALSE
   result_vec[rowSums(df)>= 2]<-'mix'
  
  return(result_vec)
}

Answer 2

Maybe you can try the code below

sapply(asplit(rbind(c1, c2, c3), 2), function(x) {
  u <- which(x == 1)
  ifelse(length(u) == 0, 0, ifelse(length(u) == 1, u, "mix"))
})

which gives

[1] "2"   "mix" "0"   "0"   "mix" "mix" "mix" "1"   "2"   "3" 

Data

c1 <- c(0, 0, 0, 0, 1, 1, 1, 1, 0, 0)
c2 <- c(1, 1, 0, 0, 1, 0, 0, 0, 1, 0)
c3 <- c(0, 1, 0, 0, 0, 1, 1, 0, 0, 1)