Automatic multiplication between vector and matrix

Question

I have this R code:

> coef
[1] 1.5 2.4 3.9 4.4
> y
     [,1] [,2] [,3] [,4]
[1,]    1    2   12   45
[2,]    5    6    7    8
[3,]    9   10    2   12
         


        

Answer 1

 apply(y, 1, "*", coef)
#  -- result --    
  [,1] [,2] [,3]  [,4]  [,5]
[1,]   1.5  7.5 13.5  19.5  25.5
[2,]   4.8 14.4 24.0  33.6  43.2
[3,]  46.8 27.3  7.8  58.5 152.1
[4,] 198.0 35.2 52.8 198.0  30.8