[R] Odp: t.test : extracting Error

[Petr PIKAL]

Hi

r-help-bounces at r-project.org napsal dne 20.11.2007 09:36:32:

> 
> Hi Thanks for the reply.
> 
> I implemented your solution to my problem but ...
> 
> For some of my column there is not enough data to do t-test so it gives 
me
> error and stops the for loop, is any graceful way to check for error msg 
and
> say ok if there is no $p.value continue to the next column

You need at least 2 values for x and 2 values for y so you can just put an 
if clause in your for loop. Something like:

for (whatever) {
if(sum(!is.na(x)>1 & sum(!is.na(y)>1) do your t.test
}

Regards
Petr


> 
> Once again thx for help.
> 
> 
> 
> sata pinal wrote:
> > 
> > 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 
> > 
> > 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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