Re: Compare two functions

Hey heaviside.

What specific thing do you want to compare? If you say "closeness", then you need to say what "closeness" is.

A typical way to compare things is to use norms and a typical norm that is useful is the 2-norm where ||f,g|| = (f(x)-g(x))^2 where the norm is Integral over some region ||f,g||dx.

Re: Compare two functions

Thanks chiro

Yes - when I wrote this, I was thinking closeness. Or similarly, identifying how different two functions are when these functions are very similar but only slightly different. I know this is a lot of handwaving since I have not specified what 'similarity' is nor 'slightly different'.

I like the 2-norm approach. I've seen it many times but didn't think about using it in this instance. However, I can see that it is a better measure than simply f-g.