On Sun, 26 Feb 2006, Matthias Fischmann wrote:
I think this is the well-known issue of using real numbers in decimal representation on a machine that thinks binary, but I don't know what to do with it, and some of you maybe do.
I want to shift+stretch a list of doubles into a given interval. example:
| x1 = [2, 3, 4, 5, 10] | y1 = normInterval x1 0 1 | => y1 = [0.0,0.125,0.25,0.375,1.0]
The function that does this looks something like this:
| normInterval :: [Double] -> Double -> Double -> [Double] | normInterval ps lower upper = map (\ x -> (x - oldLower) * stretch + lower) ps
Is there --------------------------------------------------------------^ a cancellation problem? Maybe you should use a kind of convex combination, that is (x-oldLower)*a + (oldUpper-x)*b