R help - Oct 2010 - How do I tell whether two vectors are identical?

Hi,
I have two vectors, each of length 45000.
How do I compare the vectors to ascertain if they are identical. Secondly if
they are NOT identical, how do I determine the indices of positions at which
the vectors differ?
Thanks,
Anjan


-- 
==================================anjan purkayastha, phd.
research associate
fas center for systems biology,
harvard university
52 oxford street
cambridge ma 02138
phone-703.740.6939
==================================
	[[alternative HTML version deleted]]

Try preusing an Intro to R for such elementary questions, please. Also
the R Help facility.

But...

?identical   ##(oddly enough...)
?"=="

But beware numerical issues -- see R FAQ 7.31.

-- Bert


On Tue, Oct 12, 2010 at 10:35 AM, ANJAN PURKAYASTHA
<anjan.purkayastha at gmail.com> wrote:
> Hi,
> I have two vectors, each of length 45000.
> How do I compare the vectors to ascertain if they are identical. Secondly
if
> they are NOT identical, how do I determine the indices of positions at
which
> the vectors differ?
> Thanks,
> Anjan
>
>
> --
> ==================================> anjan purkayastha, phd.
> research associate
> fas center for systems biology,
> harvard university
> 52 oxford street
> cambridge ma 02138
> phone-703.740.6939
> ==================================>
> ? ? ? ?[[alternative HTML version deleted]]
>
> ______________________________________________
> 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.
>


-- 
Bert Gunter
Genentech Nonclinical Biostatistics

And ...

?which

which(abs(x-y) >0)   # or if these are subject to FAQ 7.31, then
which( zapsmall( abs(x-y)) > 0 )

.. for second part of question.

-- David.
On Oct 12, 2010, at 1:43 PM, Bert Gunter wrote:
> Try preusing an Intro to R for such elementary questions, please. Also
> the R Help facility.
>
> But...
>
> ?identical   ##(oddly enough...)
> ?"=="
>
> But beware numerical issues -- see R FAQ 7.31.
>
> -- Bert
>
>
> On Tue, Oct 12, 2010 at 10:35 AM, ANJAN PURKAYASTHA
> <anjan.purkayastha at gmail.com> wrote:
>> Hi,
>> I have two vectors, each of length 45000.
>> How do I compare the vectors to ascertain if they are identical.  
>> Secondly if
>> they are NOT identical, how do I determine the indices of positions  
>> at which
>> the vectors differ?
>> Thanks,
>> Anjan
>>
>>
>> --
>> ==================================>> anjan purkayastha, phd.
>> research associate
>> fas center for systems biology,
>> harvard university
>> 52 oxford street
>> cambridge ma 02138
>> phone-703.740.6939
>> ==================================>>
>>        [[alternative HTML version deleted]]
>>
>> ______________________________________________
>> 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.
>>
>
>
>
> -- 
> Bert Gunter
> Genentech Nonclinical Biostatistics
>
> ______________________________________________
> 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.
David Winsemius, MD
West Hartford, CT

Or just:

id<-seq(1,45e3,1)
compare<-data.frame(id,a,b)
differences<-compare$id[a!=b]

-- 
Mi?ego dnia