there is always zero elements

Hi. right now i am tryign to learn descriptive statistics and produce them in matlab environment.

let us consider,

c = [ 1 2 3 4 5 6 7 8]

for i=1:2:length(c)

m(i)=(c(i)+c(i+1))/2;

end

disp(m)

But there is always zero elements in m. Why is this happening? how can i get m without any zero element?

Please if there is anyone to help.

Thanks in advance.

Answer 1

[Star Strider]

The reason is that your ‘i’ index skips the even-numbered elements, so the even-numbered elements are set to 0.

The easiest way to avoid that is to just use a separate counter:

c = [ 1 2 3 4 5 6 7 8]
k = 1;
for i=1:2:length(c)
    m(k)=(c(i)+c(i+1))/2;
    k = k + 1;
end
disp(m)

[Star Strider]

Actually, since you want to take the mean of adjacent pairs of elements, rather than adjacent elements, using the reshape function on your vector, and then taking the mean of the resulting matrix is likely most efficient:

m = mean(reshape(c(:), 2, []))

The result is the same.