[R] Optimization problem

[José E. Lozano]

> How about smoothing the percentages, and then take the second derrivative
to find the inflection point?
>
> which.max(diff(diff((lowess(percentages)$y))))

This solution is what I've been using so far. The only difference is that I
am smoothing the 1st derivative, since its the one I want to be smooth,
smoothing the percentages curve does not produce good results.

Thanks!
Jose Lozano