[R] multiple logical comparisons

David Winsemius dwinsemius at comcast.net
Mon Mar 22 03:19:19 CET 2010


Just read the help page:

?"%in%

"%w/o%" <- function(x,y) x[!x %in% y] #-- x without y
(1:10) %w/o% c(3,7,12)
--  
David.
On Mar 21, 2010, at 5:57 PM, Martin Batholdy wrote:

> thanks!
>
>
>
> Now I have one more question;
>
> How can I do the reverse?
> when %in% is == (for two vectors of different lengths); what is the  
> equivalent to !=  ?
>
>
>
> On 21.03.2010, at 22:33, Erik Iverson wrote:
>
>> Martin Batholdy wrote:
>>> Hi,
>>> I would like to compare a column of data with a vector.
>>> I have this data.frame for example;
>>> x <- data.frame(A = c(1:5), B = c(1,1,2,2,2))
>>> Now I have a search vector:
>>> search <- c(1,3,5)
>>> when I now try to get all the data-rows which have a 1, a 3, or a  
>>> 5 in column A and a 2 in column B, I tried this:
>>> x[x$B == 2 & x$A == search,]
>>> I hoped to get 3 2
>>> 5 2
>>> as output.
>>
>> See ?%in%
>>
>> x[x$B == 2 & x$A %in% search, ]
>>
>>
>
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