Minimizing nonsmooth single variable functions?

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What options is available if one wants to minimize a nonsmooth convex function of one variable? Subgradients would work, but there has to be some nice way of utilizing that we're only searching in 1d. Bisection would work, but are there better options?

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The Golden section search is guaranteed to converge in your case, and is a bit faster than bisection. I would use this one.

You can also consider Successive parabolic interpolation. Theoretically, it is substantially faster (superlinear convergence) but this method is rarely appropriate on its own: the parabola one gets may lead far from the minimum, especially when your function is not smooth. As the Wikipedia article mentions, this method may be used in alternation with golden section, but you'd have to first consider whether the cost of implementing a complex method like this is justified.