Roger Hui wrote: > 0. The following is a shorter equivalent for "newton": > newton=:1 : '- u % u d. 1' > Thanks for this: I should have seen it myself.
> 1. Showing convergents: > > 2. Rational numbers: > These are good examples, and I should do them. I would like to include ^:_ , since it also shows tolerant equality. Thanks, Raul, for the symbolic derivatives. On this subject, I have never quite understood the domain of d. 1 . For example: f=:***: f i:5 _25 _16 _9 _4 _1 0 1 4 9 16 25 (f d.1) 2 |domain error | (f d.1)2 f seems a perfectly reasonable function to differentiate: f' is continuous. While I would not expect this to be differentiated symbolically, I would have thought that either polynomial approximation or secant slope (the methods indicated in the Dictionary) would work. Or maybe there are stability issues? Best wishes, John ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
