R help - Dec 2010 - test whether all elements of a vector are identical

Dear list,


this might be an easy one, but I could figure out a solution (or how to 
google the right term).

Is there any way to test whether all elements of a vector are identical?

For numeric vectors I would use

sum(diff(vector)==0)==0

but I have character vectors. Any Ideas?

Cheers
Jannis

How about:
length(unique(vector)) >1

?



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On Thu, Dec 16, 2010 at 4:17 PM, Jannis <bt_jannis@yahoo.de> wrote:
> identical
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Thanks Tal. Sometimes easy solutions are close by but hard to find when 
one is focused on the wrong direction :-)!

Jannis

Tal Galili schrieb:
> How about:
> length(unique(vector)) >1
>
> ?
>
>
>
> ----------------Contact
> Details:-------------------------------------------------------
> Contact me: Tal.Galili at gmail.com |  972-52-7275845
> Read me: www.talgalili.com (Hebrew) | www.biostatistics.co.il (Hebrew) |
> www.r-statistics.com (English)
>
----------------------------------------------------------------------------------------------
>
>
>
>
> On Thu, Dec 16, 2010 at 4:17 PM, Jannis <bt_jannis at yahoo.de>
wrote:
>
>   
>> identical
>>     
>
>

On Dec 16, 2010, at 9:17 AM, Jannis wrote:
> Dear list,
>
>
> this might be an easy one, but I could figure out a solution (or how  
> to google the right term).
>
> Is there any way to test whether all elements of a vector are  
> identical?
?identical
>
> For numeric vectors I would use
>
> sum(diff(vector)==0)==0
>
> but I have character vectors. Any Ideas?
>
> Cheers
> Jannis
>
> ______________________________________________
> 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
West Hartford, CT

Hi,

The fastest way seems to be,

all(x[1] == x)


HTH,

baptiste

On 16 December 2010 15:17, Jannis <bt_jannis at yahoo.de>
wrote:
> Dear list,
>
>
> this might be an easy one, but I could figure out a solution (or how to
> google the right term).
>
> Is there any way to test whether all elements of a vector are identical?
>
> For numeric vectors I would use
>
> sum(diff(vector)==0)==0
>
> but I have character vectors. Any Ideas?
>
> Cheers
> Jannis
>
> ______________________________________________
> 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.
>

> all(vector[1]==vector)
should be quick.

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