[R] creating a file of p.values

[Peter Dalgaard]

jim holtman wrote:
> Try something like this (untested):
> 
> Pvalues <- lapply(1:25, function(x)get(paste("A", i, sep=""))$p.value)


He probably wants to start one level earlier, with the X1, etc.

How about

nm <- paste("X", 1:9, sep="")
fml <- lapply(nm, function(nm)eval(bquote(.(as.name(nm))~treatment)) )
names(fml) <- nm

dd <- as.data.frame(matrix(rnorm(300),30))
names(dd) <- nm
attach(dd)
treatment <- rep(1:3,10)
sapply(fml, function(f) kruskal.test(f)$p.value)


(This overdoes it a bit, you could also just do

sapply(dd[nm], function(x) kruskal.test(x~treatment)$p.value)

and lose the eval(bquote(....)) mess, but I was looking for a way to
loop over the model formulas, so that you don't get all response
variables called "x" if you retain the full output.)


> 
> On Wed, Nov 12, 2008 at 11:15 AM,  <lave0083 at umn.edu> wrote:
>> Hi all,
>> I am performing hundreds of kruskal wallis tests and trying to figure out
>> how to create a file of the p.values I obtain.
>>
>> This is the code I use for the tests:
>> A2<-kruskal.test(X2~treatment)
>> A3<-kruskal.test(X3~treatment)
>> A4<-kruskal.test(X4~treatment)
>> A5<-kruskal.test(X5~treatment)
>> A6<-kruskal.test(X6~treatment)
>> A7<-kruskal.test(X7~treatment)
>> A8<-kruskal.test(X8~treatment)
>> A9<-kruskal.test(X9~treatment)
>> ect
>>
>> and I can get the p values from each one individually by:
>> A2$"p.value"
>>
>> I was hoping to figure out how to make one list of all of the p values I
>> need without having to type each one seperately
>>
>> I tried
>>> list1<-list(A1$"p.value":A3$"p.value")
>>> list1
>> [[1]]
>> [1] 0.8419078
>> but you see this only gives me the first p-value when I was trying to get 3.
>>
>> I also tried
>>> list1<-list(A1$"p.value", A2$"p.value")
>>> list1
>> [[1]]
>> [1] 0.8419078
>>
>> [[2]]
>> [1] 0.1127509
>>
>> and this works but I would have to type them all out.
>> If anyone is aware of a shortcut that would be helpful. Thanks
>>
>> ______________________________________________
>> R-help at r-project.org mailing list
>> https://stat.ethz.ch/mailman/listinfo/r-help
>> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
>>
> 
> 
> 


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   O__  ---- Peter Dalgaard             Øster Farimagsgade 5, Entr.B
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