how to take the average of a matrix of any size

How do I compute the mean of all the values in a matrix of any size

Answer 1

[Wayne King]

mean()

    X = randn(100,100);
    mean(mean(X))

or

      mean(X(:))

[lowcalorie]

im sorry i meant matrix of any size

[Sean de Wolski]

X = rand(3,3,3,3,3);

[Wayne King]

If you want the means of the columns or the rows, you can use mean() with the dimension argument

X = mean(X,1);

or

X = mean(X,2);

[Honglei Chen]

Wayne's answer is for matrix of any size. Just try it out.

Answer 2

[Sean de Wolski]

mean(X(:))

or for speed:

N = numel(X);
sum(reshape(X,N,1))/N;

or for fun:

eval([repmat('mean(',1,ndims(X)) 'X' repmat(')',1,ndims(X)) ';']);

[Jan]

A strange definition of "fun".

I think, that "sum(X(:))/numel(X)" is more fun, it is even _nice_.