[R] new_index

[Jeff Newmiller]

Val has been posting to this list for almost a decade [1] so seems unlikely to be a student... but in all this time has yet to figure out how to post in plain text to avoid corruption of code on this plain text mailing list. The ability to generate small examples has improved, though execution still seems hazy. Why is there an ID column in dat2 at all?

Try

dat3 <- dat1[ 1,, drop=FALSE ]
dat3$Index <- as.matrix( dat1[ -1 ] ) %*% dat2$weight

[1] https://stat.ethz.ch/pipermail/r-help/2010-March/233533.html

On September 7, 2019 12:38:12 PM PDT, Bert Gunter <bgunter.4567 using gmail.com> wrote:
>dat1 is wrong also. It should read:
>
>dat1 <-read.table(text="ID, x, y, z
>                  A, 10,  34, 12
>                  B, 25,  42, 18
>               C, 14,  20,  8 ",sep=",",header=TRUE,stringsAsFactors=F)
>
>Is this a homework problem?  This list has a no homework policy.
>
>Cheers,
>Bert
>
>Bert Gunter
>
>"The trouble with having an open mind is that people keep coming along
>and
>sticking things into it."
>-- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )
>
>
>On Sat, Sep 7, 2019 at 12:24 PM Val <valkremk using gmail.com> wrote:
>
>> 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,
>>
>> ______________________________________________
>> R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
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>> PLEASE do read the posting guide
>> http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
>>
>
>	[[alternative HTML version deleted]]
>
>______________________________________________
>R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
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-- 
Sent from my phone. Please excuse my brevity.