[Openspace] quantile plot
m.anyadike-danes at qub.ac.uk
Tue Sep 21 09:37:47 CDT 2004
Thanks for your suggestion but ...
1. the data is expressed as a rate in this case
2. there are just a handful of real outliers (1 or 2) at each end
Is the procedure for determining the 'breakpoint' described anywhere?
From: Julia Koschinsky [mailto:koschins at uiuc.edu]
Sent: 20 September 2004 23:08
To: Michael Anyadike-Danes
Cc: Openspace at Agec221. Agecon. Uiuc. Edu
Subject: RE: [Openspace] quantile plot
One of the reasons why you can end up with different numbers of
in your quintile categories is if you are using count data that is
for instance has a lot of zeros or small numbers (as is the case with
certain mortality or risk data). In those cases, the computation of
points is unreliable because there are ties between the frequently
values. The use of rates instead of counts is more appropriate here.
Please write back if this does not address your problem.
Spatial Analysis Laboratory
University of Illinois at Urbana-Champaign
From: openspace-bounces at agec221.agecon.uiuc.edu
Behalf Of Michael Anyadike-Danes
Sent: Monday, September 20, 2004 10:32 AM
To: openspace at agec221.agecon.uiuc.edu
Subject: [Openspace] quantile plot
I have a dataset with 434 observations.
I requested a quantile map with 5 divisions (ie a quintile map).
The map has five divisions: "1st range (0); 2nd range (165); 3rd range
4th range (95); 5th range (87)".
I was expecting 5 more-or-less equal ranges (86 and/or 87).
Have I missed something?
Economic Research Institute of Northern Ireland
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