Re: [ng-spice-devel] convergence
---"Al" == Al Davis <aldavis@ieee.org> writes:
Al> Actually, both are inconsistent.
Al> With form 1, x is solved using the latest state variables, which
Al> may not match what you get using the latest x. With form 2, the
Al> state variables are solved using the latest x, which may not match
Al> what you get when you apply the state variables you have.
I'm not sure how you get "form 2" being inconsistent.
In "form 2", when the iteration quits, F and J are evaluated at x_n
and the accepted solution is x_n, so everything is consistent.
Al> But, at convergence it doesn't matter. The error is bounded.
I expect that this is often true, but given the sloppy checking in
spice, I expect that this difference could account for some timestep
problems, since, for instance, capacitor charge won't correspond to
the voltage across the branch.
--Steve
Partial thread listing:
- Re: [ng-spice-devel] convergence, (continued)