I obtained a curve numerically (see below). Apparently, the curve will converge to some value at $\infty $. How can I extract this limit value? The problem is that I do not know how this curve converges. It seems to be a power law. But I do not know the exponent.
By the way, I am sure it will converge. Actually, it is bounded by 1.
I get the curve in simulating some physical problem. It is actually some optimization process.
If it is always less than 1, try plotting $1/(1-f)$ or $\log(1-f)$ and see what it looks like.