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From: "Nasser M. Abbasi" <nma@12000.org>
Newsgroups: comp.soft-sys.matlab
References: <hd8m1p$rqq$1@fred.mathworks.com>
Subject: Re: How to fit normal distribution to histogram
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Date: Mon, 9 Nov 2009 03:31:47 -0600
Xref: news.mathworks.com comp.soft-sys.matlab:583495



"Jamal Mohamed" <in.jamal@yahoo.com> wrote in message 
news:hd8m1p$rqq$1@fred.mathworks.com...
> Hi
> How to fit normal(or any) distribution to histogram based its mode(peak) 
> for image data ?

normal dist. requires 2 parameters. mean and variance (or standard 
deviation). can't just use the peak. If you have the data itself (the sample 
from which you got the histogram from) then you can easily estimate these 
from the sample data.

If you just have the plot itself, then you can find the mean (where the peak 
is), for variance, find the area around the mean which is about 68% of total 
area, this gives you 2 standard deviations as measured on the x-axis under 
this area. But I am no expert on this so I could be off here.

(there is a statistic newgroup group btw).

--Nasser