Count peaks in a data set

Hello,

I have a set of data of volumes in the lungs by mechanical ventilation. I want to count the peaks in this data to devide the total volume by this value to get the tidal volumes. How can I get this out of a set of data? We have very much data, so our script is like this:

files=dir('*.log');
M=NaN(length(files),1);
Lek=M;
B=M;
C=M;
R=M;
PS=M;
TV=M;

for i=1:length(files)
    out=textscan(files(i).name,'M%f_Lek%f_B%f_C%f_R%f_PS%f');
 
    A = readcell(files(i).name); %data inladen
    Z = string(A);
    time = Z(7:end,1); %van time een vector maken
    time = strrep(time, ',', '.'); %komma's in vector in punten veranderen
    time = str2double(time);
    flow = Z(7:end,2);
    flow= strrep(flow, ',', '.');
    flow = str2double(flow);
    flow = flow./60;
    flowpos = flow;
    flow(flow<0)= 0;
    RR=23;
    volpos = trapz(time, flow);
    TV(i)= (volpos./RR); 
    TV(i)= TV(i).*1000;
    
   M(i)=out{1};
   Lek(i)=out{2};
   B(i)=out{3};
   C(i)=out{4};
   R(i)=out{5};
   PS(i)=out{6};
   
   
end
 T=table(M,Lek,B,C,R,PS,TV,'VariableNames',{'M','Lek','B','C','R','PS','TV'})

Because the tidal volumes vary a lot, I want to get a function which looks at the other values and not set a fixed treshold. Can anyone help me with this?

[Adam]

If you have the Signal Processing Toolbox

doc findpeaks

gives you various options to specify how to define what counts as a significant peak.

[Will Reeves]

.. and if you don't? :-) (have the signal processing toolbox)

Answer 1

[Steven Lord]

Take a look at the islocalmax function in MATLAB.