How to use findpeaks for a matrix of size A

I have a matrix of 4*8. I would like to find out the no of peaks in each row,with a condition that peak value-minimum value >1000.How should i do it.I have tried following code, but not working. i have tried [peaks]=findpeaks(A),but not working.

[Image Analyst]

Duplicate of http://www.mathworks.com/matlabcentral/answers/219521-number-of-local-maxima-with-specific-condition

Answer 1

[Star Strider]

The findpeaks function will work, but you have to cycle through the rows:

M = randi(99, 4, 8);
for k1 = 1:size(M,1)
    [pks,loc] = findpeaks(M(k1,:));
    P{k1} = [pks; loc];
end

The cell array accounts for different numbers of peaks and locations in each row.

[navan]

Can you tell me how can we find out the no of peaks in each row ?

[Salaheddin Hosseinzadeh]

Navan,

Star Strider gave you the answer! rest of it is easy.

numel(loc)

or

size(loc)

This gives the total number of locations if loc is not a matrix, which I don't think if it is.

Good luck!

[navan]

Dear Strider, Its great to see your sharing of knowledge. thanks alot for your valuable effort and time.

I have seen your latest add on to the question to find out no of peaks in each row.

I am happily saying that its great for your help and it is working. Thanks a ton. I may be needing your help to solve some more puzzle in the signal processing. so the final code is

    % code to find peaks, its location and number of peaks in each row of a matrix
M = randi(99, 4, 8);
for k1 = 1:size(M,1)
    [pks,loc] = findpeaks(M(k1,:));
    P{k1} = [pks; loc];
end
for 
k1 = 1:size(P,2)
    NrPks(k1) = size(P{k1},2);
end

[Star Strider]

My pleasure!

[navan]

I want to go one more step deep into the problem. finding the no of peaks in each row with a specific condtion (that is ) peakvalues with (peakvalue-minvalueof each row>1000)

Now i take a single row for easiness.In reality i have a big matrix.

A= [1000 8000 1000 1800 1200 4000 4800 4000 1000 1000]

the min-value of A=1000 The peak values of A= [8000 1800 5000], But the problem here is if i use ordinary threshold limit& findpeak

findpeaks(A,'Threshold',1000)
it will only compare with the values near to it.

I want to find out the total number of peaks which obey my condition (i.e>1000) in detailed way

8000-1000 >1000 (true) 1800-1000<1000(false) 5000-1000>1000(True)

so the aswer i expect peakswithcondition=2 I have also posted this as different question. Kindly see the link below

http://www.mathworks.com/matlabcentral/answers/220319-findout-the-peaks-in-each-row-of-matrix-with-specific-conditions

[Star Strider]

Answered in your different Question.