27 Feb
2006
27 Feb
'06
2:48 p.m.
On Mon, 27 Feb 2006, Matthias Fischmann wrote:
On Mon, Feb 27, 2006 at 03:11:35PM +0100, Henning Thielemann wrote:
Is there a cancellation problem?
what's a cancellation problem?
zu deutsch: Auslöschung cancellation happens for instance here: 1 + 1e-50 - 1 == 0
Maybe you should use a kind of convex combination, that is
(x-oldLower)*a + (oldUpper-x)*b
i don't quite understand this either.
You have to adjust 'a' and 'b' in order to obtain 0 on x==oldLower and 1 on x==oldUpper. The expression still depends linearly on x (plus an absolute term). Maybe it reduces the cancellations if the lower and the upper bound differ much in magnitude.