[R] Odp: Reg : using two different matrix : how to do t.test

[Petr PIKAL]

Hi

r-help-bounces at r-project.org napsal dne 19.11.2007 09:32:25:

> I have two matrix with same dimensions. I want to do t.test using each 
column 
> from 2 different matrix. 
> Row n Column names in both matrix are same. 
> 
> e.g. 
> Matrix1 
> id VC1 VC2 VC3 
> R 1 2 3 
> R1 4 5 6 
> R3 7 8 9 
> 
> 
> Matrix2 
> id VC1 VC2 VC3 
> R 10 11 12 
> R1 13 14 15 
> R3 16 17 18 
> 
> want to do t.test using each column (with same name ) using Matrix1 and 
Matrix2
> 
> for eg t.test(Matrix1$VC1, Matrix2$VC1)$p.value 

I am not sure if it is a best way but here seems to me that for cycle 
could be considered

result<-rep(NA, 3999)
for (i in 2:4000) {
result [i-1] <- t.test(mat1[,i], mat2[,i])$p.value
}

Regards
Petr

> 
> What is the best way to do it. I have dataset with 4000 columns for each 

> matrix with same row and column names. 
> 
> Thanks a lot.
> 
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