On Feb 19, 2008 6:19 AM, al davis <[EMAIL PROTECTED]> wrote: > > If there are no storage elements, there is no truncation error, > but there is still "activity", and step control is still > needed.
I agree it doesn't work well in every case but for most circuits (i.e. those with storage elements) truncation error is a reasonable estimation of the circuit activity. You are using it in trap method after all and it works quite well (except for ringing which is an inherent "feature" of trap method). > For the future, there are plans to add node-voltage-change based > time step control. That would be great, assuming it'd work reliably without manual intervention. However, I see it as a great supplement for the LTE based time step control, not a replacement for it. > Truncation error is only loosely related to circuit activity, > usually too little, too late. That is why it is still possible > to see trap ringing sometimes. What other simulators are using (spectre, hspice etc.)? Whatever it is it works well enough for them - I've never had to fiddle with their time step control options except for some tricky circuits. Again, I am quite satisfied with the results of trap method. There are some numerical artifacts but I can live with them. I would only wish euler method to perform similarly well - currently it is only usable for fixed time step transient simulations. BTW, is it possible to enable LTE check in euler method in the source code? If it's not very difficult I'd like to test it a bit. Cheers, -r. _______________________________________________ Help-gnucap mailing list [email protected] http://lists.gnu.org/mailman/listinfo/help-gnucap
