Converting Highest value of rows to 1 and rest to 0

Question

I wasn't sure if creating an if statement would be the best way, but I need code to identify the column with the highest rowmax and replace it with a 1 and the other columns of that specific row get replaced with a 0. I have about 5,000 lines of code.

I am trying to find the row with the highest max value (dataframe) and need to replace the highest row max value with a 1 and the other values with a 0 ( 6 variables/columns with 5,000 rows/obs.)

Thank you!

Answer 1

One approach in base R (similar to what Gregor Thomas already posted):

Generate example data:

df <- data.frame("row1" = c(1,2,3),
           "row2" = c(1,2,3),
           "row3" = c(1,99,3))

  row1 row2 row3
1    1    1    1
2    2    2   99
3    3    3    3

Proposed solution:

result <- t(apply(df, 1, function(x) ifelse(x == max(x), 1, 0)))

     row1 row2 row3
[1,]    1    1    1
[2,]    0    0    1
[3,]    1    1    1

Conversion back to your exact input data format:

as.data.frame(result, row.names = rownames(df), colnames = names(df))

  row1 row2 row3
1    1    1    1
2    0    0    1
3    1    1    1