The function may be used to create side generating functions from alpha-cut generators and inversely.
approxInvert(f, method = c("monoH.FC", "linear", "hyman"), n = 500)a monotonic, continuous function f: [0,1]->[0,1]
interpolation method: ``monoH.FC', ``hyman'' or ``linear''
number of interpolation points
Returns a new function, the approximate inverse of the input.
The function is a wrapper to splinefun and approxfun. Thus, interpolation is used.
Other auxiliary: convertAlpha,
convertSide