How do I add a column to a data frame consisting of minimum values from other columns?

Question

How do I add a column to a data frame consisting of the minimum values from other columns? So in this case, to create a third column that will have the values 1, 2 and 2?

df = data.frame(A = 1:3, B = 4:2)

Answer 1

You can use apply() function to do this. See below.

df$C <- apply(df, 1, min)

The second argument allows you to choose the dimension in which you want min to be applied, in this case 1, applies min to all columns in each row separately.

You can choose specific columns from the dataframe, as follows:

df$newCol <- apply(df[c('A','B')], 1, min)