Calculate the mean of an array in MATLAB

Question

I have an array in Matlab "Numbers" that is stored in the workspace as a 400x1 double. I know how to calculate the mean of this data, but the problem I have is actually writing the code to do this. I know there are functions built-in which I could use, but I want to try and calculate this using only low-level IO commands and I'm not sure how to go about doing this. I was thinking the correct way to do this would be to create a for loop and a variable containing the total that adds each element in the array until it reaches the end of the array. With that, I could simply divide the variable 'Total' by the number of elements '400' to get the mean. The main problem I have is not knowing how to get a for loop to search through each element of my array, any help in figuring that part out is much appreciated. Thank you.

There are literally thousands if not millions of examples of this online. It’s so much easier to find one of those than to ask a question here... google.com/search?q=matlab+for — Cris Luengo
mean(my_array) is not calculating the mean myself using low-level IO commands. I asked the question because all the examples I found just point to using a built-in function, but sure it's fine. — JamesW

Dan Pollard Dan Pollard · Accepted Answer · 2020-12-09T15:05:24

mean(Numbers) will do it for you. If not,

sum(Numbers)/length(Numbers)

or, if you insist on not using built-in functions,

sums = 0;
counter = 0;
for val = Numbers
    sums = sums + val;
    counter = counter + 1;
end

Numbers_mean = sums/counter;

although this will almost always be slower than just calling mean.

Calculate the mean of an array in MATLAB

1 Answers