How to take logical or of all the elements in the vector without a loop?

I am trying to use

or(a(1,1):a(1,size(a,2)))

but it doesn't run for more than 2 elements.

also when I run

or(1,1,0,0.1,0,1)

it doesn't run. It only runs for 2 inputs i.e.

or(1,0)

Is there no direct way that I can take the logical OR of elements a(1,1) to a(1,size(a,2))?

[KSSV]

Is a a matrix? What exactly you are looking for?

Answer 1

[Ameer Hamza]

or() is an operator just defined for two inputs. In case of multiple inputs, you can use any() which is equivalent to or of all elements

>> y = any([1,1,0,0,1,0,1])
y =
  logical
   1

Similarly, all() is equivalent to and of all elements

>> y = all([1,1,0,0,1,0,1])
y =
  logical
   0

Answer 2

[KSSV]

Note that you have two types of indexings in MATLAB.

1. Indexing

This is a number and should be posittive integers greater than 0. If number is negative or fracation, it will throw error.

A = rand(1,10) ; 
A(1)   % first element 
A(end)   % last element 
A(1:5)   % elements from 1 to 5 
A(-)  % error 
A(0)  % error 

2. Logical indexing

Here indices are 0 and 1's. This would be class of logical.

A = rand(1,10) ; 
idx = A>0.5 ;  % get elements greater than 0.5. 0 where conditon fails and 1 where condition mets. 
A(idx)  % this will pick the elements at the above condition satisfies 

[Jay Vaidya]

Ok, but how to do take the OR of all the elements in the row vector a = [1 0 1 1 0 1 0 0 0 1 1 0 0 1 1 1 1 1 0 0 1]?

The ans should be 1 obviously, but what is the syntax in general?

[KSSV]

idx = a | ~a ;

[Jay Vaidya]

Hello, probably I did not make it clear enough.

I want the ans = a(1,1) | a(1,2) | a(1,3) | a(1,4) incase of a 4 element vector.

In other words, I need to OR the elements

like 1 | 1 | 0 | 1 | 0 | 1 | 0 | 0.

where v is the boolean OR operator.

[KSSV]

a = [1 0 1 1 0 1 0 0 0 1 1 0 0 1 1 1 1 1 0 0 1] ;

b = a(1)|a(2) ;
for i = 3:length(a)
  b = b|a(i) ; 
end