finding mean

I have a 30 matrix of size 256x256 stored in in different variables,

for ex the variables are A,D,R,T,Y,......ETC,EACH variable has same matrix size,now i want to find mean for each matrix and store it s mean values in a separate variable ,please help

Answer 1

[the cyclist]

It's pretty awkward if there is no pattern to the naming of the variables, so if you can fix the naming problem upstream, you should try to do that. If you can't, then one approach is to define a function that takes a variable number of arguments, and does the mean of each one:

function arrayOfMeans = getMeans(varargin)

arrayOfMeans = zeros(nargin,1);
for n=1:nargin
    arrayOfMeans(n) = mean(varargin{n}(:)); % Calculating means of all elements in array
end

end

Then call that function with the list of your variables as the input. For example,

>> getMeans(magic(3),rand(7),eye(4))

In your case, you would do

>> getMeans(A,D,R,T)

etc

Answer 2

[Walter Roberson]

http://matlab.wikia.com/wiki/FAQ#How_can_I_create_variables_A1.2C_A2.2C....2CA10_in_a_loop.3F

[FIR]

walter i have seen the link .but could not find a solution ,can u please tell how to get a solution as per my post posted above

Answer 3

[Andrei Bobrov]

a = whos;
b = strcat({a(cellfun(@(x)isequal(x,[256 256]),{a.size})).name},',');
AD_etc = eval(['{',[b{:}],'}']);
AD_mean = cellfun(@(x)mean(x(:)),AD_etc,'un',0);
out = cell2struct([AD_etc;AD_mean],{'data','mean'});