[Scilab-users] find and locate local maxima

[Claus Futtrup]

Hi Stéphane

It looks very nice and I hope it will be added to Scilab as proposed by 
your code review. Why does it say in red print "Cannot Merge" ?

/Claus

On 16-03-2021 17:45, Stéphane Mottelet wrote:
>
> Hi
>
> For real life signals you should rather use something like this 
> (Savitsky-Golay filters)
>
> https://codereview.scilab.org/#/c/21499/
>
> S.
>
> Le 16/03/2021 à 17:09, CHEZE David 227480 a écrit :
>>
>> Hi Clément,
>>
>> Thank you for your quick reply and solution ! Actually it’s working 
>> for simple data but with noisy experimental timeseries, some 
>> filtering is required to get perfect regular signal (between the 
>> ‘true’ extrema) that could be then managed by the routine. I suppose 
>> this is something the Matlab/Octave is handling internally, with some 
>> parameters as function’s argument to tune it, maybe it’s not the case .
>>
>> Regards,
>>
>> David
>>
>> *De :* users <users-bounces at lists.scilab.org> *De la part de* Clément 
>> David
>> *Envoyé :* mardi 16 mars 2021 16:27
>> *À :* Users mailing list for Scilab <users at lists.scilab.org>
>> *Objet :* Re: [Scilab-users] find and locate local maxima
>>
>> Hello David,
>>
>> After reading the Matlab documentation page, it seems pretty simple 
>> to implement using Scilab : and $ symbols:
>>
>> function[*pks*, *locs*]=_findpeaks_(*data*)
>>
>> ii = find(d(1:$-2) < d(2:$-1) & d(2:$-1) >= d(3:$));
>>
>> *pks* = *data*(ii+2);
>>
>> *locs* = ii + 2;
>>
>> endfunction
>>
>> data= [25 8 15 5 6 10 10 3 1 20 7];
>>
>> _plot_(data)
>>
>> [pks,locs]= _findpeaks_(data);
>>
>> _plot_(locs,pks, 'xr');
>>
>> Note: using oct2py and pims might also be an option for simple cases 
>> but these wrappers are complex to use and data need to be copied at 
>> language boundaries.
>>
>> Regards,
>>
>> Clément
>>
>> *From:*users <users-bounces at lists.scilab.org 
>> <mailto:users-bounces at lists.scilab.org>> *On Behalf Of *CHEZE David 
>> 227480
>> *Sent:* Tuesday, March 16, 2021 2:53 PM
>> *To:* Users mailing list for Scilab <users at lists.scilab.org 
>> <mailto:users at lists.scilab.org>>
>> *Subject:* [Scilab-users] find and locate local maxima
>>
>> Hi all,
>>
>> I’m looking for function that could find and locate every local 
>> maxima of any discrete time signal (timeseries), similar to Matlab or 
>> Octave function findpeaks(), scipy find_peaks(). Is anyone aware if 
>> something similar is already available in Scilab ? (I already browsed 
>> a little bit and it don’t seem so…)
>>
>> If not in Scilab macros, any hint to use the Octave or scipy function 
>> directly from Scilab?
>>
>> More globally it seems that Octave Forge could be linked with Python 
>> (from oct2py import octave
>>
>> # Load the Octage-Forge signal package.
>>
>> octave.eval("pkg load signal")), does someone ever tried to bridge 
>> similarly in Scilab ? oct2sci
>>
>> Kind regards,
>>
>> David
>>
>>
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> -- 
> Stéphane Mottelet
> Ingénieur de recherche
> EA 4297 Transformations Intégrées de la Matière Renouvelable
> Département Génie des Procédés Industriels
> Sorbonne Universités - Université de Technologie de Compiègne
> CS 60319, 60203 Compiègne cedex
> Tel : +33(0)344234688
> http://www.utc.fr/~mottelet
>
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