I got this Error :Matrix dimensions must agree

Q1: When i input this formula ; f=(4/pi)*sum((1./n)*sin(2*pi*n.*t)) I got this error: Matrix dimensions must agree

Where n=1:2:401 and t=linspace(-0.5,0.5,250)

Q2: f=1/pi+0.5*sin(pi*tau)-2/pi*(cos(pi*n'*tau)/n'.^2-1) tau=linspace(-0.5,0.5,250); n=2:2:106; i get the same error !

Please correct it for me. And show me where are the mistakes

Answer 1

[Andrei Bobrov]

one way

%W1:
n = (1:2:401).';
t = linspace(-0.5,0.5,250);
f = 4/pi*sum(bsxfun(@times,1./n,sin(2*pi*n*t)));
%W2:
n = (2:2:106).';
tau = linspace(-0.5,0.5,250);
f = 1/pi+bsxfun(@minus,0.5*sin(pi*tau),2/pi*(bsxfun(@rdivide,cos(pi*n*tau),n.^2)-1));

[Andrei Bobrov]

corrected

[Jan]

Mohammed has written [MOVED from answer to comment section]:

But i need 250 variables for t

Answer 2

[Jan]

for the expression n .* t the variables n and t must have the same size. Perhaps you want a matrix like, e.g. created by a dyadic product:

n(:) * t

But as long as you do not specify this, n .* t is simply a bug, when the sizes differ or non of them is a scalar.

Answer 3

[Mohammed]

Non of answers work !

[Jan]

Please, Mohammed, do not post comments to answers as answer, but as comment. When you claim, that a suggested method "does not work", be so kind to show the code, the error message or an explanation of the difference between your expectation and the results.

Of course my suggestion will "not work", because I told you, that there is a bug in your code or that you at least did not tell us, what you want to achieve exactly enough. How could this be "working"?!