[R] Boot warning messages

ACroske Audy3272 at yahoo.com
Fri Aug 15 16:41:48 CEST 2008


Hello,
I am attempting to run a bootstrap on a data frame, but something is going
wrong.
I have 2 data frames:
A                        B
   V1  V2  V3            V1  V2  V3
1   1    4    7        1   10  13  16
2   2    5    8        2   11  14  17
3   3    6    9        3   12  15  18

Over each iteration of the bootstrap, I would like to perform a t.test on
the corresponding columns (i.e. t.test(A$V1,B$V1) and so on).
I wrote a function that does this, and only keeps the p.values.
However, I only want to run the bootstrap on B (I don't want to resample A,
I just need it for the t.tests).
Is this even possible?

Here's the code I have so far, and the warning messages I get
(The function works fine, its the boot command that's wrong somehow):

boot.fun2<-function(A,B){
	res1<-t.test(A$V1,B$V1)
	res2<-t.test(A$V2,B$V2)
	res3<-t.test(A$V3,B$V3)
	res.p<-list()
	res.p<-c(res1$p.value,res2$p.value,res3$p.value)
	res.p
}
boot(B,boot.fun2,R=1000)

Error in var(x) : 'x' is empty
In addition: Warning messages:
1: In A$V1 :
  $ operator is invalid for atomic vectors, returning NULL
2: In B$V2 :
  $ operator is invalid for atomic vectors, returning NULL
3: In is.na(x) : is.na() applied to non-(list or vector) of type 'NULL'
4: In mean.default(x) : argument is not numeric or logical: returning NA
> 

Any help would be greatly appreciated!
Thanks!
-- 
View this message in context: http://www.nabble.com/Boot-warning-messages-tp18999810p18999810.html
Sent from the R help mailing list archive at Nabble.com.



More information about the R-help mailing list