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Test for list membership

5 messages · Marcin Wlodarczak, Henrique Dallazuanna, Uwe Ligges +2 more

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Hi,

I need some help with this one: how do I check whether a vector is
already present in a list of vectors.

I have seen %in% recommended in a similar case but that obviously does
not work here.

c(1,2,3) %in% list(c(1,2,3), c(4,5,6))

returns

[1] FALSE FALSE FALSE

which makes sense since 1, 2 or 3 are not elements of that list. I don't
really know how to move from there though.

Best wishes,
Marcin
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Try this:

list(c(1,2,3), c(4,5,6)) %in% list(c(1,2,3))

On Mon, May 30, 2011 at 10:36 AM, Marcin Wlodarczak
<mwlodarczak at uni-bielefeld.de> wrote:

  
    
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On 30.05.2011 15:36, Marcin Wlodarczak wrote:
You said it yourself, almost:

list(c(1,2,3)) %in% list(c(1,2,3), c(4,5,6))

Uwe Ligges
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You almost solved your own problem with that last statement. Instead
of comparing apples and oranges, you need to compare oranges and
oranges:
[1] TRUE
[1] FALSE

Sarah


On Mon, May 30, 2011 at 9:36 AM, Marcin Wlodarczak
<mwlodarczak at uni-bielefeld.de> wrote:
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On 05/30/2011 04:14 PM, Uwe Ligges wrote:
Brilliant! Thanks to everyone.

Marcin