Dividing each cell in a data set by the column sum in R

Question

I am trying to divide each cell in a data frame by the sum of the column. For example, I have a data frame df:

sample   a   b   c
a2      1    4    6
a3             


        

Answer 1

You can use the transpose of the matrix and then transpose again:

t(t(as.matrix(df))/colSums(df))