How do I normalize this signal
21 Ansichten (letzte 30 Tage)
Ältere Kommentare anzeigen
Mikael
am 13 Mai 2014
Bearbeitet: Greg Dionne
am 20 Mai 2014
I have a noisy data set that I am trying to find peaks for (I am using the peakfinder function). The function works great when the baseline of the signal does not change, but when it does it no longer finds peaks well - I was thinking of filtering the data, but was unsure what kind of filter would actually help. Any help would be greatly appreciated. A sample below:
![](https://www.mathworks.com/matlabcentral/answers/uploaded_files/162617/image.jpeg)
1 Kommentar
Akzeptierte Antwort
Star Strider
am 13 Mai 2014
I suggest a low-order bandpass filter, perhaps Butterworth 3 or 4. That will eliminate your baseline drift and most of the noise, making it much easier for findpeak to work.
6 Kommentare
Weitere Antworten (2)
Greg Dionne
am 13 Mai 2014
Since your peaks appear well-defined and are spaced far enough apart, I would suggest estimating the baseline by using medfilt1().
6 Kommentare
Greg Dionne
am 20 Mai 2014
Bearbeitet: Greg Dionne
am 20 Mai 2014
OK. It might be helpful to post your data file.
If you're not comfortable posting your data... maybe try something like:
[~,locs] = findpeaks(x-medfilt1(x,100),'MinPeakHeight',.01e4)
x(locs)
Image Analyst
am 13 Mai 2014
Some of those peaks are just barely above other peaks that don't have the red circle. Are you setting some threshold for how much a peak must exceed the "baseline" signal before it can be called a peak? What about using sgolayfilt() in the Signal Processing Toolbox. I have a demo available upon request.
2 Kommentare
Image Analyst
am 15 Mai 2014
Sounds like you don't even have an interest in even trying to understand, and have decided in advance that you "can't really use it" without understanding it. For example, you haven't attached your data file to let anyone help you by trying things.
Siehe auch
Kategorien
Mehr zu EEG/MEG/ECoG finden Sie in Help Center und File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!