Array dimensions must match for binary array op

Hello, I got a problem with this error: "Array dimensions must match for binary array op", the problem is that I used to use the trial version of matlab and my code works, but now I use the licensed version and it throw me a lot of errors like that when It used not to do it. Can someone explain this?

Answer 1

[Walter Roberson]

The trial version would have been R2017a probably. But the licensed version might have been R2016a or earlier.

One of the changes in R2016b was to automatically do the equivalent of bsxfun in some cases. For example if you had

A = (1:5)';
B = [10 20 30];

then in versions up to R2016a, A+B would be an error because arrays of size 5 x 1 could not be added to arrays of size 1 x 3. But as of R2016b, the situation would be treated as being like

bsxfun(@plus, A, B)

automatically replicating data to produce the answer

    11    21    31
    12    22    32
    13    23    33
    14    24    34
    15    25    35

Your code accidentally used this feature and did something in the trial version, but then you moved over to an earlier version without the feature and the code failed.

For example your code might have X + Y but X might be a row vector and Y might be a column vector of the same length. In earlier versions that would be an error; from R2016b onwards it has been defined to do something. It might not be what you want done, but it does something.

[Ricardo Olvera]

Thank you so much :) that was the problem, and I already solved it.

[Saiful Haqiqi Hassan]

I am using r2018a. and still encountered this problem.