How can I remove a set of given peaks such as the peaks located at (7.9000,0.9989) and (14.1000, 0.9993) in the following code? I want to be able to do this even when the plot expands and has many more peaks.

t=[0:0.1:6*pi];
y=sin(t);
[pks,pk_locs] = findpeaks(y,t);
[trghs,trgh_locs] = findpeaks(-y,t);
plot(t,y);
hold on;
plot(pk_locs,pks,'^r');
plot(trgh_locs,-trghs,'vg');
hold off;

[Image Analyst]

I don't see why that won't work for any number of peaks or signal length.

You forgot to read this link. So no data, no screenshot = no answer.

Also, please read this link so you know how to format your code so that people can read it.

[dpb]

How to decide which specific peaks to remove is the bigger question...after that,

doc ismembertol

probably answers the Q?.

Answer 1

[Carlos Felipe Rengifo]

Hi, it can be done by replacing the undesired peaks by nan values. In your case, it will be:

    % The first two lines of your script
    t = [0:0.1:6*pi];
    y = sin(t);

    % I just added this line to your code
    y(ismembertol(t,[7.9,14.1],1E-3)) = nan;

    % The rest of your code
    [pks,pk_locs] = findpeaks(y,t);
    [trghs,trgh_locs] = findpeaks(-y,t);
    plot(t,y);
    hold on;
    plot(pk_locs,pks,'^r');
    plot(trgh_locs,-trghs,'vg');
    hold off;

[Edii Mason]

Thank you for your answer! That is what I want except it seems to also erase part of the sin plot and I want to only erase the peak marker while maintaining the original plot. Do you have any ideas how to do this?

[Carlos Felipe Rengifo]

In that case, I propose the following solution:

% Signal generation
t                   = 0:0.1:6*pi;
y                   = sin(t);

% Find peaks
[pks,pk_locs]       = findpeaks(y,t);
[trghs,trgh_locs]   = findpeaks(-y,t);

% Removing undesired peaks
removals            = ismembertol(pk_locs,[7.9,14.1],1E-3);
pk_locs(removals)   = [];
pks(removals)       = [];

% Plot
plot(t,y);
hold on;
plot(pk_locs,pks,'^r');
plot(trgh_locs,-trghs,'vg');
hold off;

I hope this solution meets your requirements. If that is not the case, I will be happy to try again.