Very new help needed.

Hello all R user,

I am very new with r I have been wondering whether anyone could help me.
I have a 23000 row and 273 colums. What I want to do is to calculate unit vector for every
3 colums along the row. Could you please advise me how to do that using R?

A simple example might help us to understand what it is you want.


Do you wish to convert a 23000 by 273 matrix to a 23000*3 by 273/3 matrix?

If so and your matrix is 'x',

 	dim(x) <- c( 23000*3, 273/3 )

will do.

Do you wish to find the projection of the vector (1,1,1) onto each set of 
x[ i, 1:3 + (j-1)*3 ]? Then

 	apply( array( x, dim=c(23000, 3, 273/3 ) ), c(1,3), mean )

seems like what you would want.

As is stated at the end of your email:

 	PLEASE do read the posting guide
 	http://www.R-project.org/posting-guide.html and provide commented,
 	minimal, self-contained, reproducible code.

This will make it more likely that readers of your message can help you.

with regards,
Abu

_________________________________________________________________
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Charles C. Berry                            (858) 534-2098
                                             Dept of Family/Preventive Medicine
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