MATLAB: Taking average of 3 rows from a matrix

averagematrix

I have a data that has 10 columns and 369 rows.

I would like to get average of every 3 rows so that the output will be 10 columns 123 rows.

So that I will be getting average of first three rows in the first row in the output spreadsheet.

Thank you in advance.

Best Answer

Simpler and faster than the other two:

[m,n]=size(A); % A is your matrix
Mean=reshape(mean(reshape(A,3,[])),[],n)

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MATLAB: How to sum multiple rows elements within the matrix

Hi Abdulhakim,

The mean and reshape functions are helpful for your case. Here is the code that does what is asked for.

% Consider the input matrix is a
a = rand(30,70);
% Reshape the matrix such a way you have only 3 rows
aReshape = reshape(a,3,[]); % This turns up to 3 x 700
% Use the mean function
avg = mean(aReshape); % This returns the average of 3 elements in each column (1 x 700)
% Now to get the desired ouput in matrix form, perform the reshape again
out = reshape(avg,[],70); % Output size is (10 x 70)

The links to the document page of mean and reshape functions are:

https://www.mathworks.com/help/matlab/ref/mean.html

https://www.mathworks.com/help/matlab/ref/reshape.html

Hope this helps.

Regards,

Sriram

MATLAB: How to calculate cumulative average of every n values in a matrix

B = (A(1:3:end,:)+A(2:3:end,:)+A(3:3:end,:))/3

Best Answer

Related Solutions

MATLAB: How to sum multiple rows elements within the matrix

MATLAB: How to calculate cumulative average of every n values in a matrix

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