Mean Function in MATLAB
Mean or average is the average of a sequence of numbers. In MATLAB, mean (A) returns the mean of the components of A along the first array dimension whose size doesn’t equal to 1. Suppose that A is a vector, then mean(A) returns the mean of the components. Now, if A is a Matrix form, then mean(A) returns a row vector containing the mean of every column.
Mean =
Example:
Mean of sequence x = [1,2,3,4,5] = Sum of numbers/Count of numbers
= 15/5
= 3
Different syntax of the mean() method is:
- M = mean(A)
- M = mean(A,’all’)
- M = mean(A,dim)
- M = mean(A,vecdim)
M = mean(A)
- It returns the mean of sequence A.
- If A is a vector, then it returns the mean of all elements in the vector
- If A is a matrix, then it returns a vector where each element is the mean of each column in A.
Example:
Matlab
% Input vector A = [1 2 3 4 5]; disp( "Vector :" ); disp(A); % Find mean of vector x = mean(A); disp( "Mean :" ); disp(x); |
Output:
Example:
Matlab
% Input matrix A = [1 1 2; 2 3 2; 0 1 2; 1 5 7]; disp( "Matrix :" ); disp(A); % Find mean of matrix x = mean(A); disp( "Mean :" ); disp(x); |
Output :
M = mean(A, ‘all’)
It returns the mean of all the elements in A either it can be vector or matrix.
Example:
Matlab
% Input matrix A = [1 1 2; 2 3 2; 0 1 2; 1 5 7]; disp( "Matrix :" ); disp(A); % Find mean of whole matrix x = mean(A, 'all' ); disp( "Mean :" ); disp(x); |
Output :
M = mean(A,dim)
- It returns the mean of matrix A along each of the given dim.
- If dim = 1, then it returns a vector where the mean of each column is included.
- If dim = 2, then it returns a vector where the mean of each row is included.
Example:
Matlab
% Input matrix A = [1 1 2; 2 3 2; 0 1 2; 1 5 7]; disp( "Matrix :" ); disp(A); % Find mean of each row in matrix x = mean(A,2); disp( "Mean :" ); disp(x); |
Output :
M = mean(A,vecdim)
- It returns the mean of A based on the specified dimensions vecdim in A.
- If A is a 2-by-2-by-3 array, then mean(A,[1 2]) calculates the mean of each page of size 2-by-2 as it’s considered as a single entity. So it returns the vector of size 3 as the mean of each page.
Example:
Matlab
% Creating a 2-by-3-by-3 array A(:,:,1) = [12 2; -1 1]; A(:,:,2) = [3 13; -2 10]; A(:,:,3) = [4 7 ; 3 -3]; disp( "Array :" ); disp(A); % Calculate mean of each page M1 = mean(A,[1 2]); disp( "Mean of each page :" ); disp(M1); |
Output:
Contact Us