[R] Unique Values of a Matrix

[Henrique Dallazuanna]

Or:

na.exclude(unique(c(X)))

On Fri, Feb 26, 2010 at 10:50 AM, Todd DeWees
<T.DeWees at cpse.dundee.ac.uk> wrote:
> I found that using
>
> Sort(unique(c(X)) also works to remove NA....  if you don't mind the unique values being sorted....
>
> Todd DeWees, PhD
> Statistician
> University of Dundee
> Mackenzie Building
> Kirsty Semple Way
> Dundee DD2 4BF
> Scotland UK
> PH: 01382-420119
>
>
> -----Original Message-----
> From: David Winsemius [mailto:dwinsemius at comcast.net]
> Sent: 26 February 2010 1:49 PM
> To: Henrique Dallazuanna
> Cc: Todd DeWees; r-help at r-project.org
> Subject: Re: [R] Unique Values of a Matrix
>
>
> On Feb 26, 2010, at 8:17 AM, Henrique Dallazuanna wrote:
>
>> Try this:
>>
>> unique(c(X))
>
> I did but it returned NA as did:    unique(as.vector(X)).
>
> To get rid of the NA's I needed to do:
>
> X[!duplicated(as.vector(X)) & !is.na(X)]
>
> (Logical indexing and does need as.vector() , or c() , to "straighten
> out" the index expression.)
>
> Not sure why applying the straightening to the second logical term is
> not equivalent:
>  > X[!duplicated(X) & !is.na(as.vector(X))]
> [1] 1 2 4 3 1 7 2
>
> This also:
>  > unique(c(X))[!is.na(unique(c(X)))]
> [1] 1 2 4 3 7
>
>>
>> On Fri, Feb 26, 2010 at 10:06 AM, Todd DeWees
>> <T.DeWees at cpse.dundee.ac.uk> wrote:
>>> I have a 280,000 x 11 matrix with various values and many NA
>>> values.  What I would like to do is get a vector of every unique
>>> value in the matrix.
>>>
>>> For example:
>>>
>>> X =     [ 1    2    NA
>>>          4    3      1
>>>          7  NA  2 ]
>>>
>>> Returns:
>>> Unique_X = [ 1, 2, 3, 4, 7]
>>>
>>> Thanks,
>>> Todd
>>>
>>>
>>>        [[alternative HTML version deleted]]
>>>
>>> ______________________________________________
>>> R-help at 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.
>>>
>>
>>
>>
>> --
>> Henrique Dallazuanna
>> Curitiba-Paraná-Brasil
>> 25° 25' 40" S 49° 16' 22" O
>>
>> ______________________________________________
>> R-help at 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.
>
> David Winsemius, MD
> Heritage Laboratories
> West Hartford, CT
>
>



-- 
Henrique Dallazuanna
Curitiba-Paraná-Brasil
25° 25' 40" S 49° 16' 22" O