[R] Matched pairs with two data frames

[Udo]

Zitat von Peter Alspach <PAlspach at hortresearch.co.nz>:

> Udo
>
> Seems you might want merge()
>
> HTH .......
>
> Peter Alspach

Thank you Peter and Jorge,

but as I had written in my last sentence,
"Merge doesn´t do the job, because it makes
all possible matches", but maybe there is a sophisticated
solution with "merge", I could not bring light to.

Udo




>
> > -----Original Message-----
> > From: r-help-bounces at r-project.org
> > [mailto:r-help-bounces at r-project.org] On Behalf Of Udo
> > Sent: Monday, 14 April 2008 6:41 a.m.
> > To: r-help at r-project.org
> > Subject: [R] Matched pairs with two data frames
> >
> > Hi,
> > I have a frame "treat" and want to find matched pairs in the
> > data frame "control". In the matched (combined) data frame
> > there should be two variables (0/1),indicating the "source"
> > of the data (treat or control), so that it is possibe to set
> > a "filter" (extraxt/select data).
> >
> > #Here are the dataframes (my real data frames have many
> > variables) treat <- data.frame(age=c(1,1,2,2,2,4),
> >                     school=c(10,10,20,20,20,11),
> >                     out1=c(9.5,2.3,3.3,4.1,5.9,4.6)) control
> > <- data.frame(age=c(1,1,1,1,3,2),
> >                       school=c(10,10,10,10,33,20),
> >                       out2=c(1.1,2,3.5,4.9,5.2,6.5))
> > print(treat)
> > print(control)
> >
> > matched.data.frame <- ?????? #Match "treat" "control" by age school
> >
> >
> > #My SPSS syntax would be similar to this:
> > MATCH FILES FILE="treat" /IN=fromtreat
> >   /FILE="control" /IN=fromcontrol
> >   /BY age school.
> > SELECT IF fromdad AND fromfam. #select data, set filter
> >
> > The /IN= option creates a 0/1 variable that indicates the
> > "source" of the data
> >
> > The resultand matched data frame should have the following structure:
> > age   school    out1    out2  fromtreat     fromcontrol
> > 1	10	9.5	1.1  	1		1
> > 1	10	2.3	2.0  	1		1
> > ....
> > 4	11	4.6	NA   	1		0
> > 3	33	NA	5.2	0		1
> > ....
> >
> > I tried "which" and "match", but I failed and was unlucky
> > looking at the help/archive. Merge doesn´t do the job,
> > because it makes all possible matches.
> >
> >
> > Thank´s for any help!
> > Udo
> >
> >
> > --------------------------------------------
> > Udo K    N     G
> >       Ö     I
> >
> > Clinic for Child an Adolescent Psychiatry Philipps University
> > of Marburg / Germany
> >
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> >
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--------------------------------------------
Udo K    N     G
      Ö     I

Clinic for Child an Adolescent Psychiatry
Philipps University of Marburg / Germany