# Create a plot for local max peaks given a certain time range.

1 view (last 30 days)
Shamus Sim on 10 Aug 2020
Edited: Adam Danz on 14 Aug 2020
This is the code I am running for an ECG data.
Imagine that
sf = 399.0698; %sampling frequency (Hz), samples per second
T = 1/sf;
timeSeries = T:T:600.8122; %time intervals
% graph with circled peaks (needs debugging)
[pks,locs] = findpeaks(y(1,:),'MinPeakDistance',0.3);
plot(timeseries,y(1,:),timeseries(locs),pks,'or'),xlabel('Time (s)'),ylabel('Amplitude(uV)')
%y(1,:)is the signal I have filtered; its points traverse horizontally on row 1
% timeSeries is my time intervals on my X axis
I have a signal y(1,:) with a sampling frequency of 399.0698 and the total length of signal is 600s. I have found the local max for the signal y(1,:) I would like to plot a graph such that the peaks are circled and I can choose which part of the signal to show. Example 590-591seconds.
Thank you!
Shamus Sim on 11 Aug 2020
also its an EEG signal not ECG

Adam Danz on 11 Aug 2020
It's unclear what some of your variables are and how they relate to each other. For example, what's the second row of y? How does timeSeries (1x239766) related to y (2x100)? What is x?
Here's how to circle the peaks when (x,y(1,:)) is used to plot the data.
plot(x,y(1,:))
hold on
plot(x(locs),y(1,locs), 'ro') To address the time cutoffs of 590-591, I'll need more info.
##### 2 CommentsShowHide 1 older comment
Adam Danz on 12 Aug 2020
Edited: Adam Danz on 14 Aug 2020
I'm not sure what you changed. Have you run the code you shared? It uses two different forms of the variable "timeSeries" vs "timeseries".
" I would like to plot a graph such that the peaks are circled and I can choose which part of the signal to show."
My answer shows you how to do the first part. You can apply that method to whatever variables you're using.
As for the second part about choosing which part of the signal to show, I don't know what your question is.