Gaussian fit of a peak

[Ben Abbott]

User defined.

On Sep 23, 2008, at 4:38 AM, Andrea Cimatoribus wrote:

> I am not sure I understood. Does Octave optimisation package have some
> function for fitting a gaussian, or some user defined function?
>
> 2008/9/18 Ben Abbott <bpabbott at mac.com>:
>>
>> On Sep 17, 2008, at 4:58 PM, Andrea Cimatoribus wrote:
>>
>>> In matlab, I used function "fit". Data are intensity as a function  
>>> of
>>> energy. Of course, you can think it as an histogram of event  
>>> number as
>>> a function of energy.
>>> Andrea
>>>
>>> 2008/9/17 Ben Abbott <bpabbott at mac.com>:
>>>>
>>>>
>>>> On Wednesday, September 17, 2008, at 10:20AM, "Andrea Cimatoribus"
>>>> <sambarluc at gmail.com> wrote:
>>>>>
>>>>> Hi everybody,
>>>>> I am an absolute novice of octave, even though I have some  
>>>>> experience
>>>>> with matlab.
>>>>> Just to get the feeling of octave, I am presently translating a  
>>>>> simple
>>>>> (but very useful to me) script, that basically sums data with a  
>>>>> peak
>>>>> structure. In order to do this properly, I need to centre each new
>>>>> spectrum on the zero, that is the peak maximum. My strategy, in
>>>>> matlab, was to make a preliminary gaussian fit, whose result was  
>>>>> to be
>>>>> confirmed through a graphical input, to get the "zero" of the
>>>>> spectrum. As of now, I am trying to understand how can I make a
>>>>> gaussian fit of the data in octave. Data is simply organised as a
>>>>> matrix [x,y]. Is there a built function? Sorry but I can't find
>>>>> anything with online help.
>>>>> Andrea
>>>>
>>>> How did you do it in Matlab?
>>>>
>>>> If the data is statistical, then I'd recommend you calculate the  
>>>> median
>>>> and standard deviation and construct the gaussian distribution  
>>>> from that.
>>>>
>>>> By "sums data with a peak structure" do you mean you are  
>>>> constructing a
>>>> histogram?
>>>>
>>
>> "fit" is part of the curefit toolbox, correct?
>>
>> In any event, there is a package available from MathWorks File  
>> Exchange
>> called "fit" I thought would work, but Octave's fminsearch has some  
>> trouble
>> with it. If you'd like to track down the specifics ...
>>
>>
>> http://www.mathworks.com/matlabcentral/fileexchange/loadFile.do?objectId=8468
>>
>> You'll need Octave's optimization package
>>
>>       http://octave.sourceforge.net/doc/optimization.html
>>
>> Ben
>>