Re: [Gnucap-devel] dc command

[al davis]

On Friday 13 September 2013, Felix Salfelder wrote:
> On Fri, Mar 29, 2013 at 12:27:36PM +0100, Felix Salfelder 
wrote:
> > [..]
> > an implementation and some unittests of/for the above is in
> > the gnucap-uf repo and latest tarball on tool. it quite
> > works in all cases known to me. however i cant distribute
> > it as plugin, as it needs a change in keep_ and
> > restore_voltages in u_sim_data.
> >
> > 
> >
> > please consider some of this functionality upstream, or
> > provide the needed interface (this way or another).
> > [..]
> 
> this is now in the dc-WIP branch on savannah

I've been playing with it ....

The branch has:
1. autotools, which still isn't ready for release, needs 
muntzing and testing
2. revised u_sim_data.cc
3. revised s_dc.cc

I think the best way to move forward is to incorporate the stack 
version of u_sim_data to main, after review and testing, then 
let s_dc.cc cook as a plugin for a while.

Regarding u_sim_data ...

I think it would be better to change it so it always uses the 
stack.  The old single level would be just the stack with only 
one thing on it.

If there are two ways to do something, you need:
1. one way
2. the other way
3. the code to switch between them
4. more test cases, including testing the case using the stack 
with only one thing on it.

Just the stack .. it is tested all over the place.

Regardless, it needs a test to be sure it is properly emptied.

Regarding s_dc.cc ....

Looks interesting .. much derived from the transient code.

I noticed some failed regressions and questionable regressions.

Failed regressions:
It breaks the A to D conversion.  It seems that all analog nodes 
are reported to have logic value "4.21" which means unknown, not 
valid logic.

Questionable regressions:
Some tests, most notably trcurve*, give different results.  At 
first glance, the differences seem insignificant, might be an 
improvement, but this needs to be explained.