Multiplying all columns in dataframe by single column

Question

I know it is a basic quaestion but couldnt find any solution to it. I want to multiply all columns of a dataframe by single column.

df1<-data.frame(F1=c(1         


        

Answer 1

We can vectorize the multiplication by replicating the 'C' column

df1 * C[row(df1)]
#     F1   F2   F3
#1  2.0  2.0  2.0
#2  5.0  5.0  5.0
#3 16.0 16.0 16.0
#4  4.5  4.5  4.5

Or use the rep explicitly

df1 * rep(C$C, ncol(df1))