If you're still working on it, I'd love to see the second derivative from the data. That's what I'm wondering about most these days: Are we at the inflection point or not?
The turning point is when the second derivative is zero, which would indeed be easy to spot with a second derivative graph. But it’s also very easy to spot with the first derivative graph (as published by the FT now): It’s when the first derivative hits its maximum.
Yes- but I'm talking about the inflection point- where the curve goes from concave up to concave down. These are modeled as gaussians- so if that modeling works we would be a standard deviation from the peak- assuming the crisis is being well managed.
By turning point I mean the inflection point. You turn from “driving left” (convex) to “driving right” (concave).
By the way, the derivative of the logistic function is the logistic distribution, and that’s not the Gaussian bell shape, it has much fatter tails: Gaussian tails drop much faster, with exp(-x^2), while the logistic drops with exp(-|x|). (Makes sense, as the logistic curve grows exponentially at the beginning, and the derivative of the exponential is the exponential.)
haha yes indeed. I had never heard the term "turning point" used like that, but I guess it makes sense if you think about it as the turning point of the first derivative.
But I learned what a logistic function is, so thank you. I guess that is needed for the cumulative count.
You might be interested in this. I posted it a few days ago- it's why I'm talking Gaussians.
