[R] new_index

[Val]

Hi  all

Correction for my previous posting.
dat2 should be read as
dat2 <-read.table(text="ID, weight
A,  0.25
B,  0.42
C,  0.65 ",sep=",",header=TRUE,stringsAsFactors=F)

On Sat, Sep 7, 2019 at 1:46 PM Val <valkremk using gmail.com> wrote:
>
> Hi All,
>
> I have two data frames   with thousand  rows  and several columns. My
> samples of the data frames are shown below
>
> dat1 <-read.table(text="ID, x, y, z
> ID , x, y, z
> A, 10,  34, 12
> B, 25,  42, 18
> C, 14,  20,  8 ",sep=",",header=TRUE,stringsAsFactors=F)
>
> dat2 <-read.table(text="ID, x, y, z
> ID, weight
> A,  0.25
> B,  0.42
> C,  0.65 ",sep=",",header=TRUE,stringsAsFactors=F)
>
> My goal is to  create an index value  for each ID  by mutliplying the
> first row of dat1 by the second  column of dat2.
>
>   (10*0.25 ) + (34*0.42) + (12*0.65)=  24.58
>   (25*0.25 ) + (42*0.42) + (18*0.65)=  35.59
>   (14*0.25 ) + (20*0.42) + (  8*0.65)=  19.03
>
> The  desired out put is
> dat3
> ID, Index
> A 24.58
> B  35.59
> C  19.03
>
> How do I do it in an efficent way?
>
> Thank you,