A UIImageView or UIImage Subclass With Other Methods

Question

Gentleones,

I would like (at another's suggestion) to extend the functionality of a UIImageView or UIImage so that I can display a particular image in a view and ask it about itself. Since it's a graph, I'd like to be able to ask this particular UIImageView what a particular Y value is returned given a particular X value.

(Ignore creating the graph programmatically. Can't do that for other reasons. Anywho...)

But--now pay attention here!--I'm a n00b! I have successfully written a program that displays the image using addSubView and some other stuff, so I know a little. Enough to be dangerous, anyway.

Can somebody help me out with the best choice (UIImageView or UIImage) and the best way to extend that class so that I can load the image and later query it for relevant info?

Thanks in advance,
Bill