[R] Create a unique group id

[PIKAL Petr]

Hi

Your question was formated in HTML and therefore came scrammbled. Post in plain text. And preferably use dput for posting data.

Regards

Petr

> -----Original Message-----
> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-
> project.org] On Behalf Of Norbi Gurracho
> Sent: Thursday, January 02, 2014 12:33 PM
> To: r-help at r-project.org
> Subject: [R] Create a unique group id
> 
> I have a following sample data frame. How can I create a group id of
> column and b and to obtain column c? a	b	c 1	1	1 1	1
> 	1 1	1	1 1	2	2 1	2	2 1	2	2 1	3	3 1
> 	3	3 1	3	3 2	1	4 2	1	4 2	1	4 2	2
> 	5 2	2	5 2	2	5 2	2	5
> 	[[alternative HTML version deleted]]
> 
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