How to find peaks in matrix the rest are 0

A = randi(50,7,11) %sample matrix
A = 7×11
    31    11    34     5    45    26    34    50    40    30    43
    25    42    25    48    46    25    42     1    27    15    25
    30     3     1    10    22    34    47    13    17    44     4
    15    11    17    34    23    36    44    36    46     1    33
    37    43    16    38    45    46     4     1     4     9    30
    29    25    26    20    19    48     8    10    37    47     6
     1    36    39    16    48    45    45    33    26    31     8
B=zeros(size(A));
for i=1:size(A,1)
    for j=1:size(A,2)
        M = zeros(size(A));
        M(i,j) = 1;
        if all(A(i,j)>A(conv2(M,[1,1,1;1,0,1;1,1,1],'same')>0)) %checking if A(i,j) is local maxima
            B(i,j)=A(i,j);
        end
    end
end
B
B = 7×11
     0     0     0     0     0     0     0    50     0     0    43
     0    42     0    48     0     0     0     0     0     0     0
     0     0     0     0     0     0    47     0     0     0     0
     0     0     0     0     0     0     0     0    46     0     0
     0    43     0     0     0     0     0     0     0     0     0
     0     0     0     0     0     0     0     0     0    47     0
     0     0    39     0     0     0     0     0     0     0     0

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pzaksek 2022-6-10

Your speed, help, kindness, ... is amazing and fantastic.

THANK YOU!!!!!!!!!!

Dyuman Joshi 2022-6-10

You are welcome!!!

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Answer 2

pzaksek 2022-6-10

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https://ww2.mathworks.cn/matlabcentral/answers/1737720-how-to-find-peaks-in-matrix-the-rest-are-0#answer_982825

编辑：pzaksek 2022-6-10

My intention is to show that i would like to peaks (...Matrixes are dimensons 100x 200

I don't know how many peaks are there? How big they are ? I don’t know their position in the matrix?

the code should derivate adjacent places so long that only 1 number for each peak remains. the surrounding towns are 0s.

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Answer 3

pzaksek 2022-6-11

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此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1737720-how-to-find-peaks-in-matrix-the-rest-are-0#answer_983550

hello, you helped me a lot :)

But I would ask for more help.

From the dataset, I can draw the areas (imshow (sitesMat2, [])) where the events took place. I have to find the highs (maximum) in this area. Areas are changing inside the matrix ... This picture and database is simple. Later, there are many more of these areas. I added a database. You can also draw a 3D image that will answer certain questions about the complexity of the problem.

Is there a way or option for matte code to look for maxima in these circles, which vary in size depending on the location ...Must find only one maximum :)The above code is great, but it finds me multiple maxima in the same area.