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

?setdiff

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

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.



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