Distance between two pixels but belonging to different sets

How can I find the distance between two pixels belonging to two different sets? I think pdist does that but for a single object?

Thanks.

[Image Analyst]

What is a "set"? Is it a variable? Like a 2D image array? Or a N by 2 array of (x,y) coordinates? Why won't the Pythagorean theorem work or hypot() work for you?

[med-sweng]

@Image Analyst. The set will be a vector of values

[Jan]

So you want the distance between two "pixels" "belonging" to two different vectors. What does this mean? Could you give an example?

[Image Analyst]

If that's all I get to work with, then let me just say I'm out. I don't know. Good luck though.