I think Rowan Constable wrote: > which batches the rules located in rules.clp everytime the method is > called. This approach works fine but it is REALLY slow.
Jess's rule compiler is actually really quick; hundreds of rules can be compiled in a fraction of a second. What takes time is pattern matching. If working memory is full of facts, then reloading the rules can take a long time because all the pattern matching has to be redone. > Is there anyway of speeding this up? I tried batching the rules in > the constructor of the class and it is dramatically faster but > store-fetch doesn't work properly then. This results in every > material given the same suitability (20%). I tried to remedy this by > clearing the storage of rule engine using clearStorage but this > throws up a null-pointer exception. Whether or what rules are defined will have no effect at all on how store and fetch work; they're just thin wrappers over calls to HashMap.set() and get(). What you need to get a handle on what is happening during your program. First of all, given that reloading rules is slow, it sounds like pattern-matching takes a while. You can often speed this up dramatically by writing your rules properly. The FAQ has a little info about this, as does the "Rete Algorithm" chapter of the manual. Use the tools that Jess gives you (the view, watch, and matches commands) to monitor what Jess is doing and look for large numbers of partial matches. Second, the reason that you get the wrong answer depending on where you load your rules is not that Jess cares, but that changing when things are called changes the sequence of operations that you're asking Jess to do. Loading the rules just once is absolutely fine -- but you may need to fully or partially reset working memory for each run, depending on how your rules are written. But unless you're writing rules that themselves add or remove other rules, there's no reason to ever reload the rules. My main advice is to use "watch" to make sure you understand when your facts are coming in, what rules are activated, what rules fire, and when. Understand the prerequisites for your rules, and then make sure that when you call "run", things are in the proper state. --------------------------------------------------------- Ernest Friedman-Hill Advanced Software Research Phone: (925) 294-2154 Sandia National Labs FAX: (925) 294-2234 PO Box 969, MS 9012 [EMAIL PROTECTED] Livermore, CA 94550 http://herzberg.ca.sandia.gov -------------------------------------------------------------------- To unsubscribe, send the words 'unsubscribe jess-users [EMAIL PROTECTED]' in the BODY of a message to [EMAIL PROTECTED], NOT to the list (use your own address!) List problems? Notify [EMAIL PROTECTED] --------------------------------------------------------------------
