How to multiple the vector and variables from dataframe
At Sun, 30 Dec 2012 18:26:45 +0800 (CST),
meng wrote:
hi all: Here's a dataframe(dat) and a vector(z): dat: x1 x2 x3 0.2 1.2 2.5 0.5 2 5 0.8 3 6.2
z
[1] 10 100 100 I wanna do the following: 10*x1,100*x2,1000*x3 My solution is using the loop for z and dat(since the length of z is the same as ncol of dat),which is tedious. I wanna an efficient solution to do it .
You could convert the data frame to a matrix:
dat=data.frame(x1=1:3, x2=11:13) dat
x1 x2 1 1 11 2 2 12 3 3 13
as.matrix(dat) * c(3, 2)
x1 x2 [1,] 3 22 [2,] 4 36 [3,] 9 26 Neal