./ and .* operations

I have two versions of matlab one is 2015b and other is 2019a an operation ./ works in 2019a version but shows error matrix dimension mismatch in other 2015b version how come?

[G A]

https://blogs.mathworks.com/loren/2016/10/24/matlab-arithmetic-expands-in-r2016b/

[per isakson]

Most likely, you have made a mistake.

Can you show us a small example that throws this error in R2015b?

Answer 1

[Guillaume]

As per G A's comment, R2016b introduced automatic expansion for compatible array sizes. So, this works in R2016b or later:

x = [1, 2, 3]    %1 x 3 row vector  
y = [1; 1; 1]    %1 x 3 column vector
z = x .* y       %results in a 3 x 3 matrix

whereas it would fail in earlier versions.

To obtain the same result in earlier versions, use bsxfun

z = bsxfun(@times, x, y)   %times is the functional name of .*