Multiply two terms at a set distance apart from each other in an array

So, say you have a row vector of 950 values. And you want to find the multiplication between 2 terms 23 elements apart, like 1 and 24, 2 and 25, 3 and 26 etc until 927 and 950. How can this be done?

I have written a for loop but it gives me an error.

Loop:

for i = 1:950
    var = array(i+23)*array(i)
end

Error:

Index of array exceeds 950

Any help would be greatly appreciated. Thanks.

[Jan]

Note: "var" is a built-in Matlab function. After shadowing it by using this as name of a variable, you cannot call var() anymore.

Answer 1

[Stephen Cobeldick]

The MATLAB approach:

v = arr(1:end-23) .* arr(24:end);

Answer 2

[源樹 上林]

array = 1:950;
for i = 1:950
    disp([ 'i = ' num2str(i) ' : array(' num2str( i+23 ) ')*array(' num2str( i ) ')' ])
    var = array(i+23)*array(i)
end

array(951) does not exist.

Answer 3

[Jan]

The loop method:

array = rand(1, 950);
for i = 1:950 - 23
    v = array(i+23) * array(i)
end

Stephen's vectorized approach is nicer and faster.