Thanks much for your perceptive response .
Computing a couple more ratios ( of ratios ) here :
In the B1 ratio column , the ratio of the largest ratio
to the smallest ratio is more than 2.1 .
In the # of curves ratio column , the ratio of the largest ratio
to the smallest ratio is more than 2 .
Their Figure 2. , albeit logarithmic , doesn't suggest such wide
variation .
There must be a lot of detail that doesn't appear in the paper ,
but I don't see any function in the paper which would produce
changes in the sign of the second derivatives =
the roller coasters .
