comp.lang.idl-pvwave archive: archive » Re: compute quartiles of a distribution

Home » Public Forums » archive » Re: compute quartiles of a distribution

Show: Today's Messages :: Show Polls :: Message Navigator
E-mail to friend

Re: compute quartiles of a distribution [message #77916 is a reply to message #77914]

Tue, 18 October 2011 09:25

David Fanning
Messages: 11724
Registered: August 2001

Senior Member

bing999 writes:

> The procedures in summary.pro and cgBoxPlot.pro compute "real"
> quartiles. Actually, I should not have used this word in my case i
> guess.
>
> What I want is the interval [M-Q;M+Q] which encompass 75% of the
> values of the sample around the mean (not the median) value M, where Q
> is unique (i.e the same at lower and higher values around M). I do not
> want the 37.5% above M and the 37.5% below. It makes a little
> difference with what is calculated with your routines.
> The idea would be to span the sample starting from the mean, and
> counting the points at lower and higher values around the mean in an
> iterative manner, until I have counted 75% of sample. This would give
> the value of Q at which the 75% is reached. I have a crude idea to do
> that with for loops but it will take forever...

I'm guessing you are going to have a hard time
explaining to your reviewers why your "fake"
quartiles are better than the statistically
justifiable real quartiles. :-)

Cheers,

David

--
David Fanning, Ph.D.
Fanning Software Consulting, Inc.
Coyote's Guide to IDL Programming: http://www.idlcoyote.com/
Sepore ma de ni thui. ("Perhaps thou speakest truth.")

Report message to a moderator

[Message index]

		Re: compute quartiles of a distribution By: Jeremy Bailin on Tue, 18 October 2011 21:32
		Re: compute quartiles of a distribution By: Jeremy Bailin on Tue, 18 October 2011 12:48
		Re: compute quartiles of a distribution By: Brian Wolven on Tue, 18 October 2011 10:38
		Re: compute quartiles of a distribution By: Thibault Garel on Tue, 18 October 2011 09:36
		Re: compute quartiles of a distribution By: David Fanning on Tue, 18 October 2011 09:25
		Re: compute quartiles of a distribution By: Thibault Garel on Tue, 18 October 2011 09:12
		Re: compute quartiles of a distribution By: Thibault Garel on Tue, 18 October 2011 09:13
		Re: compute quartiles of a distribution By: David Fanning on Mon, 17 October 2011 18:26
		Re: compute quartiles of a distribution By: Vincent Sarago on Mon, 17 October 2011 06:05

Previous Topic:	Re: Pass variables into Newton or BROYDEN for solving non-linear equations
Next Topic:	ITT Suggestion box

-=] Back to Top [=-

[ Syndicate this forum (XML) ] [

] [

]

Current Time: Sat Oct 11 07:48:30 PDT 2025

Total time taken to generate the page: 1.04071 seconds