MATLAB: A(a(a>3)<10) = OK ; a(a>3 && a<10) = wrong!, the correct way

a=[1 2 3 4 11 33]; I want to get the number in a from 4-9; a(a(a>3)<10) is right; a(a>3 && a<10) is wrong — is there other correct way to make this ?

If you want to get only values between 3 and 10 (excluding the endpoints), the correct way would be:

a(a>3 & a<10)

(Not exactly sure what you meant by 'OK' but a(a(a>3)<10) definitely gives some unexpected results.)

I suspect you want bsxfun() . Try

bsxfun(@times, a.', b)

That’s actually fairly straightforward. You’re assigning a (3x1) vector vector of zeros to a scaler Xhat(i). That won’t work. Either:

Xhat(i) = 0;                % Scalar Assignment

or:

Xhat(i,:) = zeroes(3,1);    % Vector Assignment

You later refer to a subscripted ‘Xhat’. so the second version is likely what you want.