[R] Are any values in one list contained within a second list

[William Dunlap]

> -----Original Message-----
> From: r-help-bounces at r-project.org 
> [mailto:r-help-bounces at r-project.org] On Behalf Of GL
> Sent: Sunday, June 13, 2010 11:18 AM
> To: r-help at r-project.org
> Subject: [R] Are any values in one list contained within a second list
> 
> 
> Silly question, but, can I test to see if any value of list a 
> is contained in
> list b without doing a loop?

It is almost the same as your English description of the problem:
  any(a %in% b)

> A loop is easy enough, but 
> wanted to see if
> there was a cleaner way. By way of example:
> 
> List 1: a, b, c, d, e, f, g
> 
> List 2: z, y, x, w, v, u, b

It would be nicer if you used R syntax to create the
datasets in your example.  E.g., I'm guessing you mean
     a1 <- c("a","b","c","d","e","f","g")
but since you didn't quote the strings and you called it
a "list" you could mean
     a2 <- as.list(expression(a, b, c, d, e, f, g))
or, equivalently,
     a3 <- list(quote(a), quote(b), quote(c), quote(d), quote(e),
quote(f), quote(g))

Bill Dunlap
Spotfire, TIBCO Software
wdunlap tibco.com  

> 
> Return true, since both lists contain b
> 
> List 1: a, b, c, d, e, f, g
> 
> List 2: z, y, x, w, v, u, t
> 
> Return false, since the lists have no mutual values
> 
> 
> 
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ined-within-a-second-list-tp2253637p2253637.html
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