Andrei Alexandrescu Wrote: > On 04/24/2010 12:52 PM, strtr wrote: > > Walter Bright Wrote: > > > >> strtr wrote: > >>> Portability will become more important as evo algos get used > >>> more. Especially in combination with threshold functions. The > >>> computer will generate/optimize all input/intermediate values > >>> itself and executing the program on higher precision machines > >>> might give totally different outputs. > >> > >> > >> You've got a bad algorithm if increasing the precision breaks it. > > > > No, I don't. All algorithms using threshold functions which have been > > generated using evolutionary algorithms will break by changing the > > precision. That is, you will need to retrain them. The point of most > > of these algorithms(eg. neural networks) is that you don't know what > > is happening in it. > > I'm not an expert in GA, but I can tell that a neural network that is > dependent on precision is badly broken. How can you tell?
> Any NN's transfer function must > be smooth. http://www.doc.ic.ac.uk/~nd/surprise_96/journal/vol4/cs11/report.html#Transfer%20Function It wasn't for nothing I mentioned threshold functions Especially in the more complex spiking neural networks bases on dynamical systems, thresholds are kind of important.