I have a variable (FTA) that has 2 options (yes or no), and I want to create a dummy variable to replace it with yes=1 and no=0. From time period (t) 3 and onwards, it should equal 1, and before that should be 0.
df<-dummy.data.frame(df, names=c("FTA"), sep="_")
After inputting this line of code, I can't see any difference from before when I view the summary of the data (it still counts the number of no's and yes's in the column below the variable name).
I also tried doing:
dummy <- as.numeric(t >= 3)
dummy2 <- as.numeric(t < 3)
As well as:
ifelse(t >=3, 1, 0)
But I still can't observe any changes in the summary. Have I done this correctly, and what can I do to view the dummy variable I created and to replace the old one with it?
Edit: Example of data
My goal is to create a dummy variable that replaces "FTA".
Is this what you want? (Based on the value 4 as the critical watershed in the OP)
# Data:
t <- c(1:10)
FTA <- sample(c("yes", "no"), 10, replace = T)
df <- data.frame(t, FTA)
df
t FTA
1 1 yes
2 2 yes
3 3 yes
4 4 no
5 5 no
6 6 no
7 7 yes
8 8 no
9 9 yes
10 10 yes
# Change `FTA` based on two conditions:
df$new <-ifelse(df$t >= 4 &df$FTA=="yes", 1,
ifelse(df$t >= 4 &df$FTA=="no", 0, as.character(df$FTA)))
df
t FTA new
1 1 yes yes
2 2 yes yes
3 3 yes yes
4 4 no 0
5 5 no 0
6 6 no 0
7 7 yes 1
8 8 no 0
9 9 yes 1
10 10 yes 1