[Dclib-devel] Root-finding algorithm in DLib

[Zhoulai <ze...@gm...>]

Hello,

I am new to Dlib,  but I am surprised that  there is no root-finding
procedures in Dlib. Although  the functionality provided by the
optmization.h should also be able to solve root-finding problems, I guess
that comes with a higher complexity?

So what if I want to solve a problem as follows using Dlib?

I have a one dimensional function 'f' which is not necessarily
differentiable. I want to find a root 'r' that is closest  to an initial
guess 'g' so that f(r)=0 ?

More formally, I am looking for a low-cost way to  minimize |r-g|
under the constraint f(r)=0;

In my problem setting, it is likely the initial guess is the root, thus I
would use 'g' as an initial guess. However, I do not have an interval [a,b]
such that f(a).f(b)<0 which is a common request for most root-finding
procedures.

Of course the problem above can be handled by the optimization approaches
like find_min_single_variable etc, but my guess is that it can also treated
as a root-finding problem which is less expensive.  What do you think?

Thank you for your ideas.

Sncerely,
Zhoulai