I need help with a question: I have a matrix of 100 rows and 4 columns and im suppose to take the average of each column without using the mean function. The output is suppose to be a 1 row by 4 column matrix but i just get a single answer.

if true
  % code
end
function y = calc_average(y)
%    input variable y is a matrix
%    output variable x is vector
%    x is average of columns of y
[rows, columns] = size(y);
n = numel(y);
  avg = 0;
  for k = 1:n
      avg = avg + y(k);
  end
  y = avg/n;
end  % function end statement

Answer 1

[Rafael Hernandez-Walls]

If you can not use the MEAN function then you can use any other function! What if you use the SUM function in the following way! Assuming you have an A matrix:

A=rand(100,4);
p=sum(A)/100

I hope this suggestion will help you.

Regards

R.

[Lawson Chandler]

The one part i forgot is that it has to be in a "for loop"

Answer 2

[Roger Stafford]

If y is your matrix, and you must use a for-loop, do this:

n = size(y,2);
v = zeros(1,n);
for k = 1:n
  v(k) = sum(y(:,k))/n;
end