bound.quad: Build a piecewise-quadratic envelope for a given function
In jmhewitt/dsdive: Discrete Space Models for Dive Trajectories of Animals

Build a piecewise-quadratic envelope for a given function

1	bound.quad(breaks, f, df, ddf.sup, anchors = breaks[1:(length(breaks) - 1)])

`breaks`	Breakpoints that define the start and end points of each interval over which a piecewise-quadratic function will be defined.
`f`	Value of f at the breakpoints.
`df`	Derivative of f evaluated at the start of each interval.
`ddf.sup`	Supremum of second derivative of f over each interval
`anchors`	Locations within the intervals (defined by `breaks`) at which the polynomial approximation will be centered