calculating ratios to find optimal grid layout

[madscijr]

I have no idea what this is supposed to do.
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What exactly is this supposed to be doing here?

For example, say you have 15 picture
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it lets you know how many pictures you would need to add or remove for a perfect fit (if needed).

A good, clear explanation of something that I for one have tried to do several times, with limited success. 
I await with bated breath a simple (and brief) rendition.

Thanks for the warm / enthusiastic response! I think I frustrated poor Steve and if that was the only reaction I was going to get, I'd feel like I need to hire a writer to better explain my programs, LoL. 

The real trick is going to be figuring that out for a mixed bag of pictures of different orientations (up/down or longways) and sizes. Currently version 1 assumes all of a uniform size and perfectly square. It shouldn't be too hard to modify to handle non-square (where all are the same orientation), but I haven't yet thought about mixed orientation or size, or a good way to automatically arrange them so as to fit best AND be aesthetically pleasing (not too random but not too regular). I have a feeling that could open a Pandora's box of sub-problems, so my current plan is to present as simple a layout as possible, then let the user tweak it by moving the pictures around with the mouse...

EDIT: removed extraneous quoting to preserve mouse wheels and people's eyes and sanity