How to take RMS of every 10 values in a matrix and output this?

I have a matrix of 66,000 x 4 and am needing to take an RMS of every 10 values, reducing it to 6600 x 4. I am not sure the best way to code this so any help greatly appreciated. It is to allow me to perform some signal processing and compare to another matrix. Thanks in advance!

Answer 1

[Star Strider]

Try this:

A = randi(9, 66000, 4);                         % Create Matrix
Ar = reshape(A, [], 4, 10);                     % Reshape
A_RMS = sqrt(mean(Ar.^2, 3));                   % Calculate RMS

[Lara Severne]

that worked perfectly thanks for your help!

[Star Strider]

As always, my pleasure!

If my Answer helped you solve your problem, please Accept it!

[Akira Agata]

Something weird...

Please try the following as an input A. In this case, every 4 columns are the same, so every 4 columns of A_RMS should be also the same. But the result is not.

A = repmat(randi(9, 66000, 1),1,4);

Answer 2

[Akira Agata]

Another possible solution:

A = randi(9, 66000, 4);       % Sample matrix
g = repelem([1:6600]',10);    % Create group ID
func = @(x) sqrt(mean(x.^2)); % RMS function
A_RMS = splitapply(func,A,g); % Apply RMS function for each group

[Lara Severne]

okay thank you! Will trial this too!