Nick Knauer Nick Knauer - 11 months ago 48
R Question

If Column Contains String then enter value for that row

I have a dataframe that looks like this:

ABC1 0
DEF2 4
DEG0 4

How do I transform this so that if a row contains the letter "D" then insert the value "yes" in a new column and "no" if not.

Final dataframe should look like this:

ABC1 0 no
DEF2 4 yes
DEG0 4 yes

Answer Source

We can use grepl to return a logical index by matching the 'D' in the 'A' column, and then with ifelse, change the logical vector to 'yes' and 'no'

df$C <- ifelse(grepl("D", df$A), "yes", "no")