Re: QQ plot x-axis values ['Watchdog': checked]

["Li, Timothy - BLS" <Li.Timothy@bls.gov>]

S-plus appears to be using the formula (k-0.375)/(n+0.25) that is advocated elsewhere on the internet. See http://www.tau.ac.il/cc/pages/docs/sas8/stat/chap55/sect44.htm

 

and

 

http://www.okstate.edu/sas/v8/saspdf/qc/chap10.pdf#search=%22construction%20of%20q-q%20plot%22

 

Tim

---

From: s-news-owner@lists.biostat.wustl.edu [mailto:s-news-owner@lists.biostat.wustl.edu] On Behalf Of Paul Matthias Diderichsen
Sent: Tuesday, October 10, 2006 9:57 AM
To: Paul Matthias Diderichsen
Cc: s-news@lists.biostat.wustl.edu; s-news-owner@lists.biostat.wustl.edu
Subject: Re: [S] QQ plot x-axis values ['Watchdog': checked]

Dear S-plus users again. 

s-news-owner@lists.biostat.wustl.edu wrote on 
10.10.2006 15:40:12:
> Of course, there's still one issue: There seems to 
be a discrepancy 
> between what wikipedia says and what S-plus does. 

Apparently, S-plus selects the midpoint of 
n intervals between 0 and 1 for it's horizontal values in qqmath. Of course, for 
n->infinity the sets used by S-plus and wikipedia converge. But which one is 
"most right" for finite/small n? 

Thanks 
again, PMD. 
============================================================================================================================
The 
information contained in this communication is confidential, may be subject to 
legal privileges, may constitute inside information, and is intended only for 
the use of the addressee. It is the property of Abbott Laboratories or its 
relevant affiliate. Unauthorized use, disclosure or copying of this 
communication or any part thereof is strictly prohibited and may be unlawful. If 
you have received this communication in error, please notify Abbott Laboratories 
immediately by return e-mail and destroy this communication and all copies 
thereof, including all attachments.
=============================================================================================================================