Matrix dimension not agree in matrix vector operation

I'm trying to perform matrix vector element wise operation for example

rand(3) - [1,2,3]

I get error of Matrix dimensions must agree. However, this would work on my friend's machine. Similarly

    rand(3) .* [1,2,3]

would not work on my machine but on hers. I'm expecting same behavior as bsxfun(@times, rand(3), [1,2,3]) My Matlab version is 2015b and hers' is 2016b. I thought this was supported long time ago?

Answer 1

[David Goodmanson]

Hello Christine, One of the quirkier aspects of Matlab is that rand(n) and some similar functions give you a square matrix, 3x3 in this case, so neither of the commands you show will to work. You can't subtract a row vector from a matrix, at least not with that syntax. It is not clear what is happening with your friend's setup but those commands will not work in Matlab 2016b either.

Answer 2

[Steven Lord]

The feature where some operators (like the minus operator - ) automatically perform implicit expansion was introduced in release R2016b. You can read more about it on Loren's blog. For earlier releases you will need to use bsxfun.