[R] help on "stack" function

[Gabor Grothendieck]

Check out ?reshape . 

 <combe <at> b3e.jussieu.fr> writes:

: 
: So in fact :
: 
: I have a data wich colnames are :
: "id","VEMS5A","VEMS6A","VEMS7A","VEMS8A","VEMS9A","VEMS10A","VEMS11A","VEMS12
A","VEMS13A","VEMS14A","VEMS15A","VEMS16A","VEMS17A","VEMS18A","cohort")
: 
: With "VEMS5A" is the value when the subject (id) was 5 year 
old,... "VEMS18A" is
: the value when the subject(id) was 18 year old
: 
: I want to make a new data wich colnames will be :  "id","age", and "VEMS"
: Where "age" will be the age when the value in "VEMS" was measured for the 
suject
: "id"...
: 
: So I need to copy all the values of the columns "VEMS5A",... "VEMS18A" 
in "VEMS"
: and in "id" the "id" corresponding and in "age" the values between 5 and 18
: corresponding to the age of the subject when the mesure was done. And this 
only
: when the value in "cohort" was 1.
: 
: -----Message d'origine-----
: De : F Z [mailto:gerifalte28 <at> hotmail.com] 
: Envoyé : jeudi 3 février 2005 19:38
: Ã : combe <at> b3e.jussieu.fr; R-help <at> stat.math.ethz.ch
: Objet : RE: [R] he^lp on "stack" function
: 
: In the future please be a little more specific with your questions. i.e. 
: give us an example of your data  the way it looks now and the way you want 
: it to look.
: 
: I think what you want is something like:
: 
: time<-seq(as.Date("2005/1/1"), as.Date("2005/1/10"), "days")
: age<-round(runif(10,30,50))
: measure<-rnorm(10)
: mydat<-data.frame(time=time,age=age,measure=measure) #creates a data frame 
: with your 3 #variables
: 
:          time age    measure
: 1  2005-01-01  48 -1.2873181
: 2  2005-01-02  50  0.5776001
: 3  2005-01-03  44  0.1892008
: 4  2005-01-04  38  0.4981651
: 5  2005-01-05  49 -1.7591745
: 6  2005-01-06  37 -0.8898464
: 7  2005-01-07  30  0.7528217
: 8  2005-01-08  46 -1.2421763
: 9  2005-01-09  39 -0.9333667
: 10 2005-01-10  32  1.2086509
: 
: #suppose you only want patients older than 40 Older40<-mydat[age>=40,c(1,3)]
:         time    measure
: 1 2005-01-01 -1.2873181
: 2 2005-01-02  0.5776001
: 3 2005-01-03  0.1892008
: 5 2005-01-05 -1.7591745
: 8 2005-01-08 -1.2421763
: 
: Is this what you wanted to do?
: 
: Francisco
: 
: >From: "" <combe <at> b3e.jussieu.fr>
: >To: "" <R-help <at> stat.math.ethz.ch>
: >Subject: [R] he^lp on "stack" function
: >Date: Thu,  3 Feb 2005 18:10:24 +0100
: >
: >
: >
: >
: >Excuse me.
: >I don't understant how to use the function "stack".
: >I'm not sure to know the good syntax.
: >
: >I've got a data witch column names are the time when the mesures was 
: >done
: >and
: >an
: >other who indicates the age of the subjetcs.
: >I would like to do a new matrix with patients older than a value and the 
: >new
: >matrix will contain in the first column the time of the mesures and in the
: >second th evalue of the mesure.
: >
: >Could you help me please ?
: >
: >______________________________________________
: >R-help <at> stat.math.ethz.ch mailing list 
: >https://stat.ethz.ch/mailman/listinfo/r-help
: >PLEASE do read the posting guide!
: >http://www.R-project.org/posting-guide.html
: 
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