R help - Jul 2010 - Issue with write.table and read.table : I'm not getting out what I put in

Hello,

I am trying to save a large matrix of values in a file. My problem is that I am
writing 
write.table(allpos,'control_chr1.txt', dec=".")
and then I want to check it with
test2=read.table('control_chr1.txt')
sum(test2[,2]==allpos[,2])

This last number is lower than the length of the test2[,2] vector. This is
really annoying me because I can't figure out why I don't get out the
same thing
that I put in.

Why not use 'save' & 'load'?

On Mon, Jul 5, 2010 at 11:49 AM, Irina <irina.krier at epfl.ch>
wrote:
> Hello,
>
> I am trying to save a large matrix of values in a file. My problem is that
I am
> writing
> write.table(allpos,'control_chr1.txt', dec=".")
> and then I want to check it with
> test2=read.table('control_chr1.txt')
> sum(test2[,2]==allpos[,2])
>
> This last number is lower than the length of the test2[,2] vector. This is
> really annoying me because I can't figure out why I don't get out
the same thing
> that I put in.
>
> ______________________________________________
> 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.
>


-- 
Jim Holtman
Cincinnati, OH
+1 513 646 9390

What is the problem that you are trying to solve?

On Jul 5, 2010, at 11:49 AM, Irina wrote:
> Hello,
>
> I am trying to save a large matrix of values in a file. My problem  
> is that I am
> writing
> write.table(allpos,'control_chr1.txt', dec=".")
> and then I want to check it with
> test2=read.table('control_chr1.txt')
> sum(test2[,2]==allpos[,2])
>
> This last number is lower than the length of the test2[,2] vector.  
> This is
> really annoying me because I can't figure out why I don't get out  
> the same thing
> that I put in.
>
Many potential problems could underly getting FALSE for an "==" test.
One might be FAQ 7.31. Another might be encoding or locale issues  
related to the decimal separator. Why not post a reproducible example?

-- 

David Winsemius, MD
West Hartford, CT