[R] Dividing a vector into ntiles

[Chuck Cleland]

?quantile

quantile(runif(1000), probs=seq(0,1,1/3))

John Sorkin wrote:
> R 2.1.1
> Win 2k
>  
> Would someone suggest a method (or methods) that can be used to
> determine ntile cutpoints of a vector, i.e. to determine values that can
> be used to divide a vector into thirds such as 0-33 centile, 34-66
> centile, 67-100 centile. If for example I had a vector:
> 1,2,3,4,5,6,7,8,9
> and wanted to divide the vector into thirds
> I would have cut-points of 3, and 6.
> Thanks,
> John
>  
> John Sorkin M.D., Ph.D.
> Chief, Biostatistics and Informatics
> Baltimore VA Medical Center GRECC and
> University of Maryland School of Medicine Claude Pepper OAIC
>  
> University of Maryland School of Medicine
> Division of Gerontology
> Baltimore VA Medical Center
> 10 North Greene Street
> GRECC (BT/18/GR)
> Baltimore, MD 21201-1524
>  
> 410-605-7119 
> -- NOTE NEW EMAIL ADDRESS:
> jsorkin at grecc.umaryland.edu
> 
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-- 
Chuck Cleland, Ph.D.
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