r - multiply each cell of a data.frame with it's weight -

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what want embarrassing simple - nevertheless fail.

i have data.frame "characters" , "numerics". 1 of columns of data.frame represents weights.

i want multiply every cell of data frame corresponding weight (if it's numeric).

how do (best without using nested loop).

thank in advance!

example:

   c1   c2   w    l1 abc  2    1 l2 dxf  3    0.5 l3 ghi  4    1.5

should become

   c1   c2   w    l1 abc  2    1 l2 dxf  1.5  0.5 l3 ghi  6    1.5

for reproducible example, dd data frame mixture of variable types, w being weights.

dd <- data.frame(g=gl(2,2), x=rnorm(4), y=1l:4l, z=letters[1:4], w=0.3:3.3) num.vars <- names(dd)[sapply(dd, is.numeric)]  #select numeric variables num.vars <- setdiff(num.vars, "w")  # remove weight variable dd[num.vars] <- dd[num.vars] * dd$w  # multiply

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