What is wrong with this MATLAB code? Vectorizing a For-loop

Question

I want to compute the sum of 1/((1^2)(3^2))+ 1/((3^2)(5^2))+1/((5^2)(7^2))+ ...

The following code is my attempt at computing that sum with no looping:

n = 1000;
t0 = clock;    %vectorizing we get 
x1 = (1./(1:2:n)).^2;
y1 = (1/(3:2:n)).^2y1.*x1;
t = sum(y1.*x1)etime(clock,t0)

But MATLAB gives an error that the vector sizes do not agree.

How can I fix this to get the correct answer?

I see that someone already provided the answer for the specific case, but given the error message I would have suggested you to check the size of all vectors and see which one is not what you expected. — Dennis Jaheruddin
– Dennis Jaheruddin, Commented Oct 8, 2016 at 15:10

Stack Player · Accepted Answer · 2015-08-23 20:56:54Z

5

y1=(1/(3:2:n)).^2y1.*x1;

should be:

y1=(1/(3:2:n+2)).^2;

answered Aug 23, 2015 at 20:53

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3 Comments

Thanks a lot I am new here :), let me check ;)

no problem, if it works out then select my answer so other people can benefit from it!

anytime, this is what the website is for!