Request: Support Implicit Expansion with Arithmetic Operations

[VestOfHolding]

Is your feature request related to a problem? Please describe.
When doing arithmetic operations on two matrices that aren't exactly the same size, but still compatible, I would like an option for the arithmetic operation to move forward anyway.

Describe the solution you'd like
MathWorks has a feature called implicit expansion that I believe would be really useful here as well.

[apete]

I assume you want operations on matrices/arrays like this: https://se.mathworks.com/help/matlab/matlab_prog/compatible-array-sizes-for-basic-operations.html

Some variant of that could be supported. Any suggestions on how to implement this in ojAlgo?

[VestOfHolding]

Yes, that's correct.

I'm still kind of new to all this, so I'm not sure at the moment. I just noticed that this was a really neat feature that MathWorks/Matlab has that none of the active Java matrix libraries I've seen have, so it would be a cool way to stand out if added. Though on the page I linked, I do notice it talks about some of the code it generates when it realizes it needs to do the implicit expansion, if any ideas can be gained from that.

EDIT: Realized I missed half a sentence from my original post, so I've fixed that.

[apete]

I've added some support for this in a branch named Compatible-Array-Sizes that I may include in a future version.

There are new methods fillCompatile(...), modifyCompatile(...) and onCompatile(...) to complement the already existing "fill", "modify" and "on" methods.

The factory interfaces got methods to construct instances of compatible sizes/shapes.

Vector space method like "add" and "subtract" have been redefined to no longer throw exceptions if dimensions are not equal, but instead broadcast/repeat rows or columns.