How to find peaks in matrix the rest are 0

Hello

Im asking for help. It's more complicated than I know about matlab ...

for clarification and explanation I use excel....

I have a data matrix (see picture). I would like to find different peakses. Other values becomes 0 (see picture 2).

thank you so much for the help

Peter

[Dyuman Joshi]

Please show proper data, without blue bubbles. Show the whole input data and the corresponding output data.

Answer 1

[Dyuman Joshi]

Run a double for loop through all the elements

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

[pzaksek]

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

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

[Dyuman Joshi]

You are welcome!!!

Answer 2

[pzaksek]

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.

Answer 3

[pzaksek]

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.

I’ve added pictures for areas where I need to find highs(maximums).

thank you all in advance

[Dyuman Joshi]

Please ask this as another question. (MATLAB Answers etiquette) In that way, others can also help you incase I can't.

[pzaksek]

Thank you very much, you are very kind.