How to find the latest peak value of a curve.

Hello,

I have a problem, i want to find the latest peak value of the following power curve. It is not the maximum power point, i've already found it earlier. But i should compare the latest value P(end) with P(end-1) and if P(end)<P(end-1) we should continue like this... to reach the point where P(i)>P(i-1) to come one value before, it will give me the latest peak power value.

Thank's for your help ;) Jb

[Jean-Baptiste DUCAT]

I've tried with findpeak function but it return me an error message:

>> PV=plot(U,P)

PV =

Line with properties:

              Color: [0 0.4470 0.7410]
          LineStyle: '-'
          LineWidth: 0.5000
             Marker: 'none'
         MarkerSize: 6
    MarkerFaceColor: 'none'
              XData: [1x262 double]
              YData: [1x262 double]
              ZData: [1x0 double]

Show all properties

>> findpeaks(PV)
Error using findpeaks
Expected Y to be one of these types:

numeric

Instead its type was matlab.graphics.chart.primitive.Line.

Error in findpeaks>parse_inputs (line 191)
validateattributes(Yin,{'numeric'},{'nonempty','real','vector'},...

Error in findpeaks (line 134)
  = parse_inputs(Yin,varargin{:});

[Jiro Doke]

findpeaks takes a numeric vector as the input. That's what the error "Expected Y to be numeric" means.

Answer 1

[Jiro Doke]

[pk,loc] = findpeaks(P(end:-1:1),'NPeaks',1);
[U(end-loc+1) pk]

[Jean-Baptiste DUCAT]

It's exactely that thank's !! ;)

Answer 2

[Adam]

If you have the Signal Processing Toolbox just use findpeaks, if not since you only want the last peak even a simple loop running from the end of the trace forward and stopping when you reach a point where you stop increasing would do the job.

[Jean-Baptiste DUCAT]

I've already done that but it's ok i've the right answer now thank's for all ;)