Splitting responses (as numbers) into multiple columns

Question

I've survey results (categorical) stored in csv file with multiple responses within the same cell. I'd like to split it into separate column (dummy variables)

The data looks like

response <-c(1,2,3,123)
df <-data.frame(response)

I tried the code below

for(t in unique(df$response))
{df[paste("response",t,sep="")] <- ifelse(df$response==t,1,0)}

the result is here, but it created a new column for 123

head(df)
response response1 response2 response3 response123
1        1         1         0         0           0
2        2         0         1         0           0
3        3         0         0         1           0
4      123         0         0         0           1

I'd like the data to look as below

response response1 response2 response3
1        1         1         0         0
2        2         0         1         0
3        3         0         0         1
4      123         1         1         1

Appreciate your help and advice :)

`cbind(df, model.matrix(~factor(response)-1, df))` then reset the names. — lmo, Sep 04 '17 at 17:23

score 1 · Accepted Answer · answered Sep 04 '17 at 17:25

1

We can do

df1 <- cbind(df, +(sapply(1:3, grepl, x = df$response)))
colnames(df1)[-1] <- paste0("response", colnames(df1)[-1])
df1
#   response response1 response2 response3
#1        1         1         0         0
#2        2         0         1         0
#3        3         0         0         1
#4      123         1         1         1

answered Sep 04 '17 at 17:25

akrun

789,025
32
460
575

Would you please let me know if there's a way to include it in the same df? Thanks a lot! – osbwh Sep 04 '17 at 18:18
@Omar Then just update the `df` object i.e. `df – akrun Sep 04 '17 at 18:19

Splitting responses (as numbers) into multiple columns

1 Answers1