Creating one new column in R from the input of multiple existing columns

Question

I have typical survey style data in R. Multiple columns with binary -- yes/no -- records. I'm looking to create a single, categorical column based on those columns.

We'll call the dataframe schools

    PreK  Kindergarten First Second Third Fourth ... 
1    yes      yes       no     no    no    no 
2    no       no        yes    yes   yes   yes

I'd like the new column to look like this

                                         ...       Grades
1                                                 prek, kg
2                                                 elementary

I thought it might need to have to be a lot of nested ifelse strings. It goes up to 14 columns, and the new "grades" column will need to be diverse enough to address any combination of grades (e.g. 6 - 12).

I'm trying to create a new column based on the values of already existing columns. Those existing columns are all YES and NO (like checkmarks). I want the new column to reflect categories that bin together the YES values. Say, one row has YES in the "ninth", "tenth", "eleventh" and "twelfth" column, I want that to translate into "high school" in the new column.

Hi. Your question is a bit unclear. - (I) Can you provide a small example that people can replicate? - (II) What is that new column you want to, the words you write in there hare different from the names of the data frame you defined first. - (III) Is the column supposed to be a new column of the same data.frame? — Daniel, Jul 19 '16 at 20:03
Sorry about that. I'm trying to create a new column based on the values of already existing columns. Those existing columns are all YES and NO (like checkmarks). I want the new column to reflect categories that bin together the YES values. Say, one row has YES in the "ninth", "tenth", "eleventh" and "twelfth" column, I want that to translate into "high school" in the new column. — rip_ryan, Jul 19 '16 at 20:09
Great! Please add that description to your question above by editing it — Daniel, Jul 19 '16 at 20:11
Possible duplicate of [Call apply-like function on each row of dataframe with multiple arguments from each row](http://stackoverflow.com/questions/15059076/call-apply-like-function-on-each-row-of-dataframe-with-multiple-arguments-from-e) — David, Jul 19 '16 at 20:17
The new column needs to be original categories (like "elementary" or "high school") Yes the column is supposed to be of the data.frame — rip_ryan, Jul 19 '16 at 20:19

score 0 · Accepted Answer · answered Jul 20 '16 at 02:47

We can use apply with MARGIN =1 to loop over the rows

df1$Grades <-  apply(df1, 1, FUN = function(x) {
      i1 <- x=="yes"
      if(any(i1[-(1:2)])) "elementary" else toString(tolower(names(df1)[i1]))})

data

df1 <- structure(list(PreK = c("yes", "no"), Kindergarten = c("yes", 
"no"), First = c("no", "yes"), Second = c("no", "yes"), Third = c("no", 
"yes"), Fourth = c("no", "yes")), .Names = c("PreK", "Kindergarten", 
"First", "Second", "Third", "Fourth"), class = "data.frame", 
row.names = c("1", "2"))

Thank you, I'll give it a try! – rip_ryan Jul 20 '16 at 14:46 — rip_ryan, Jul 20 '16 at 14:46

Creating one new column in R from the input of multiple existing columns

1 Answers1

data