[R] R command to compare two vectors? [SEC=UNCLASSIFIED]

[Roy Mendelssohn]

> ?setdiff
>
> Description
> Performs set union, intersection, (asymmetric!) difference, equality  
> and membership on two vectors.
>

Note the (asymmetric) on difference.

-Roy

On Feb 4, 2009, at 5:06 PM, Jin.Li at ga.gov.au wrote:

> Try this:
>> a_tmp<-c("a", "b", "d", "e", "f", "g", 'h')
>> b_tmp<-c("a", "c", "e", "g")
>> setdiff(b_tmp, a_tmp)
> [1] "c"
>> setdiff(a_tmp, b_tmp)
> [1] "b" "d" "f" "h"
> Is this a bug?
> Jin
> -----Original Message-----
> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org 
> ] On Behalf Of Gabor Grothendieck
> Sent: Thursday, 5 February 2009 11:07
> To: Jorge Ivan Velez
> Cc: R-help at r-project.org
> Subject: Re: [R] R command to compare two vectors?
>
> Here is one other way:
>
> bnota <- setdiff(b_tmp, a_tmp)
>
> gives the members of b_tmp that are not in a_tmp so length(bnota) == 0
> if all of b_tmp is in a_tmp.
>
> On Wed, Feb 4, 2009 at 6:56 PM, Jorge Ivan Velez
> <jorgeivanvelez at gmail.com> wrote:
>> Dear Jason,
>> Yes, here is one way:
>>
>>> a_tmp<-c("a", "b", "c", "d", "e", "f", "g", 'h')
>>> b_tmp<-c("a", "c", "e", "g")
>>> b_tmp %in% a_tmp
>> [1] TRUE TRUE TRUE TRUE
>>> b_tmp[b_tmp%in%a_tmp]
>> [1] "a" "c" "e" "g"
>>> all(b_tmp %in% a_tmp)
>> [1] TRUE
>>
>> Take a look at ?"%in%" and ?all for more information.
>>
>> HTH,
>>
>> Jorge
>>
>>
>> On Wed, Feb 4, 2009 at 6:49 PM, Jason Rupert  
>> <jasonkrupert at yahoo.com> wrote:
>>
>>> By any chance is there an R command to compare two vectors?
>>>
>>> For example,
>>> a_tmp<-c("a", "b", "c", "d", "e", "f", "g", 'h')
>>> b_tmp<-c("a", "c", "e", "g")
>>>
>>> I would like to compare b_tmp against a_tmp to determine if the  
>>> members of
>>> b_tmp are part of a_tmp.
>>>
>>> I tried
>>> subset(b_tmp, b_tmp==a_tmp)
>>>
>>> That doesn't seem to work.
>>>
>>> Thanks again.
>>>
>>>
>>>
>>>       [[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.
>>>
>>>
>>
>>       [[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.
>>
>
> ______________________________________________
> 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.
>
> ______________________________________________
> 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.

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**********************
Roy Mendelssohn
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NOAA/NMFS
Environmental Research Division
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