How to find seven peaks in matrix 8192X8192?

Question

Daniel Fonsêca 2018-9-20

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编辑： jonas 2018-9-20

Hello! I'm trying to find the seven tallest peaks from a matrix whose dimension is 8192X8192. I'm using the following programm:

 function [h,hs,w,ws]=la(MC)
for i=1:1024 %laço para determinar os picos e comprimentos dos picos
    [pks{i},w{i}] = findpeaks(MC(i,:)); %'findpeaks' função que indica os picos e comprimentos dos picos.
    % ATENÇÃO: Só dá para fazer isso usando cell array.
end
 hs = cell2mat(pks);%Função que armazena um vetor oriundo da converção do cell array para double.
ws = cell2mat(w);%Função que armazena um vetor oriundo da converção do cell array para double.
k =size(hs);%Dimensão do vetor hs. Será usado mais a frente nos próximos laços.
h = zeros(40,1);%Valor que armazenará a maior altura realizado pela comparação.
in = zeros(40,1);%Armazenará o indice da maior altura.
b=0;
for i=1:k(1,2)% for de comparação
    if 1000<hs(1,i)%Comparação
        b=b+1;
        h(b,1) = hs(1,i);
        in(b,1) = i;
    end
end

With the function findpeaks, I find too many peaks. I've thougth use the seven tallest peaks, what dou you think?

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Answer 1

jonas 2018-9-20

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编辑：jonas 2018-9-20

在 MATLAB Online 中打开

What do you mean highest peaks? Highest prominence? Highest peak value?

The syntax of findpeaks is the following:

[Peaks,Locs,Width,Prom]=findpeaks(x)

The output variables store the peak values, their index, their width and their prominence. Let's say you find n>7 peaks, but you are only interested in the 7 tallest ones, based on their peak value. Let's extract those

[nPeaks,id]=maxk(peaks,7)

and their locations

[nLocs]=Locs(id)

Simple as that. If you are interested in the maximum prominence, just adjust the code accordingly.