A Flash demo for this
http://noppa5.pc.helsinki.fi/koe/flash/distrib/mixture7.html

Juha

On Mon, 03 May 2004 10:36:35 -0700, Peter Flom wrote:

> A mixture of normals can have just about any shape (see the book Finite
> Mixture Models by McLachlan and Peel, which has, near the beginning, a
> small bestiary of distributions generated with mixtures of normals.); it
> need not be normal, or even remotely close to normal, if you allow the
> means and variances to vary.
> 
> It could be unimodal, even if the means differ.  One way this could
> happen is if the means are relatively close, compared to the variances. 
> 
> 
> HTH
> 
> Peter
> 
> Peter L. Flom, PhD
> Assistant Director, Statistics and Data Analysis Core
> Center for Drug Use and HIV Research
> National Development and Research Institutes
> 71 W. 23rd St
> www.peterflom.com
> New York, NY 10010
> (212) 845-4485 (voice)
> (917) 438-0894 (fax)
> 
> 
>>>> [EMAIL PROTECTED] 05/03/04 1:29 PM >>>
> Although apparently "a mixture of two normals, differing in means, can
> still
> be unimodal" (orig. Everitt, 1981 "Bimodality and the nature of
> depression") -- which I don't quite 'see' yet.
> 
> ----- Original Message ----- 
> From: "rd3d" <[EMAIL PROTECTED]>
> To: <[EMAIL PROTECTED]>
> Sent: Monday, May 03, 2004 10:41 AM
> Subject: [edstat] Mixture of normal distributions
> 
> 
>> I would like to know if the mixture of normal distributions is also
>> considered a normal distribution (with mean and variance of the
> mixture as
>> parameters).
>> If one looks at the graph of the mixture, it is not really
> bell-shaped, so
>> I am wondering if it can still be normally distributed.
>>
>> .
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