MATLAB: Mean of specific rows from one column

columnmeanrows

Hi,

I want to find the mean of specific rows from one column, for example if I want to find the mean of rows 1, 3, 5, 6 and 7. How do I do this? I have attached an image of what this column looks like.

Thank you.

Best Answer

This might work: mean(A([1, 3, 5, 6:7]))

Related Solutions

MATLAB: How to calculate the mean of certain rows of a matrix based on specific column values

This works:

A = [ 123 1; 444 2; 634 1; 311 1; 111 2; 222 1; 312 1];
Amean = accumarray(A(:,2), A(:,1), [], @mean)           % Calculate Means
AmeanMtx = [Amean [1;2]]                                % Amean For The Appropriate Column #2 (For Demonstration Only, Can Be Deleted)
Aresd = A(:,1)-Amean(A(:,2))                            % Use The Second Column To Index ‘Amean’ To Calculate The Residuals
Amean =
        320.4
        277.5
AmeanMtx =
        320.4            1
        277.5            2
Aresd =
       -197.4
        166.5
        313.6
         -9.4
       -166.5
        -98.4
         -8.4

EDIT — Added comment documentation.

MATLAB: Matrix number of rows reduction to a smaller number of rows.

Use this:

 % A is your input matrix and B is squeezed matrix
  for i=1:n
    idx=find(i==A(:,1));
    B(i,:)=mean(A(idx,:),1);
  end

Best Answer

Related Solutions

MATLAB: How to calculate the mean of certain rows of a matrix based on specific column values

MATLAB: Matrix number of rows reduction to a smaller number of rows.

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