R help - Feb 2009 - R command to compare two vectors?

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.  


      
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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@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@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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Try:
> b_tmp %in% a_tmp
You may also want to use the all or any function with the above.

Hope this helps,

-- 
Gregory (Greg) L. Snow Ph.D.
Statistical Data Center
Intermountain Healthcare
greg.snow at imail.org
801.408.8111

> -----Original Message-----
> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-
> project.org] On Behalf Of Jason Rupert
> Sent: Wednesday, February 04, 2009 4:50 PM
> To: R-help at r-project.org
> Subject: [R] R command to compare two vectors?
> 
> 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]]

Jason Rupert writes:
> 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)
It depends on what you want to do.  identical() will give you simple 
TRUE/FALSE results, setdiff() will list elements only found in one vector. 
 Using the %in% operator is another good possibility.

cur

-- 
Curt Seeliger, Data Ranger
Raytheon Information Services - Contractor to ORD
seeliger.curt@epa.gov
541/754-4638

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