envelope rms implementation review
19 views (last 30 days)
Show older comments
I am trying to implement the moving RMS by Matlab.
x = randn(50, 1);
xRMS = sqrt(movmean(x.^2, 21));
xRMSref = envelope(x, 21, 'rms');
plot(xRMSref,'DisplayName','xRMSref');hold on;plot(xRMS,'DisplayName','xRMS');hold off;
legend()
Why my estimation differs from Matlab's? What actually implemented by Matlab? The algorithm description is not delailed and movrms function is locked...
1 Comment
Nim Pim
on 8 Nov 2021
Hi. I too found that moving RMS function of dsp tool box not giving the correct values. I tried it on a small data set and the manually calculated values were different. So confusing....
Answers (1)
Chunru
on 8 Nov 2021
Edited: Chunru
on 8 Nov 2021
"envelope" removes the mean first before doing movrms and it restore the mean offset in the end.
If you nake sure the signal is 0-mean, then the results would be quite same.
x = randn(50, 1);
x = x -mean(x);
xRMS = sqrt(movmean(x.^2, 21));
xRMSref = envelope(x, 21, 'rms');
plot(xRMSref,'DisplayName','xRMSref');
hold on;
plot(xRMS,'DisplayName','xRMS');hold off;
legend()
0 Comments
See Also
Categories
Find more on Multirate Signal Processing in Help Center and File Exchange
Products
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!