Xor(A, B), does A, B have to be the same dimension?

https://www.mathworks.com/help/matlab/ref/xor.html

C = xor(A,B) performs a logical exclusive-OR of arrays A and B and returns an array containing elements set to either logical 1 (true) or logical 0 (false). So, A and B has to be the same dimension so it could compare, right? But in the example, A is a 1*2; while B is a 2*1 dimension matrix.

Can anyone help me explain it?

Thanks,

[Stephen23]

"So, A and B has to be the same dimension so it could compare, right?"

No.

"Can anyone help me explain it?"

The XOR documentation states that they have to be compatible sizes:

https://www.mathworks.com/help/matlab/matlab_prog/compatible-array-sizes-for-basic-operations.html

[Feiyang Bai]

Hi,

Thanks for the explaning and extra resource. I appreciate it.

Feiyang

Answer 1

[DGM]

The arguments don't necessarily need to have the same size/shape, but they need to have compatible size/shape. Like many things in modern versions, implicit array expansion applies here. I imagine the example in the docs is something like:

xor([0 1],[0;1]) % xor two vectors

ans = 2×2 logical array
   0   1
   1   0

which is equivalent to

xor([0 1; 0 1],[0 0; 1 1]) % the two vectors expanded to a common array size

ans = 2×2 logical array
   0   1
   1   0

Consider the similarity:

plus([1 2 3 4],[1;2]) % add two vectors

ans = 2×4

2 3 4 5 3 4 5 6

[Feiyang Bai]

Hi,

Thanks for the answer. It helped a lot.

Appreciate.

Feiyang