Find out if X out of Y elements of an array are true

I have an array of 5 elements. The array is updated at any index (1,2,3,4,5) in each simulation time to a value TRUE or FALSE. In the next function, I should check if 4 out of 5 elements including the last updated element of the array are TRUE. Is there a way to check this?

Answer 1

[Jos (10584)]

Let TF be your logical array and X the index of the last updated element then

ConditionIsMet = TF(x) && sum(TF) == 4

will be true if your condition is met.

[A VP]

This works. Thank you.

Answer 2

[Arvind Sathyanarayanan]

You can do something like this :

X=sum(Array(:) == 1);
if X>=4
    disp('4 or more elements are true')
end

If they are 1s and 0s, you can just count the non zero elements using the nnz() function.

[A VP]

This solves part of my question to check if sum >= 4, but does not consider the head index that was last updated. The answer posted below solved the problem.

Thank you.

[Jos (10584)]

Logically, when one element changes at a time, (let's say, the k-th), the condition that 4 out of 5 are ture, is met can only happen when that element has become true. So, logically, that check is not really necessary ...

[A VP]

Ok. This is a new learning to me. Thank you.