Multiply many columns by a specific other column in R with data.table?

Question

I have a large data.table in R with several columns with dollar values. In a different column I have an inflation adjustment number. I am trying to figure out how to update

Answer 1

Since you can use dplyr on data.tables, you could also do:

library(dplyr)
DT %>% mutate_each(funs(.*deflator), starts_with("inc"))

Which will multiply each column of DT that starts with "inc" by the "deflator" column.