Create several dummy variables from one string variable

Question

I\'ve tried pretty much everything from this similar question, but I can\'t get the results everyone else seems to be getting. This is my problem:

I have a data fram

Answer 1

I've found a workaround. It seems that concat.split.expanded works if you have a string variable containing nothing but separators and numbers, i.e.:

> profs <- data.frame(teaches = c("1", "1, 2", "2, 3", "1, 2, 3"))
> profs
  teaches
1       1
2    1, 2
3    2, 3
4 1, 2, 3

Now concat.split.expanded works as on Dummy variables from a string variable:

> concat.split.expanded(profs, "teaches", fill = 0, drop = TRUE)
  teaches_1 teaches_2 teaches_3
1         1         0         0
2         1         1         0
3         0         1         1
4         1         1         1

However, I'm still looking for a solution which doesn't involve removing all letters from my teaches variable.