Re: [Gnucap-devel] a bug? (was: Re: Unstable inverter isn't unstable)

[al davis]

On Wednesday 05 March 2014, Felix Salfelder wrote:
> a good opportuniuty to report something i consider a bug...

It is.

Thank you.

> if that is true, i suspect that tr_begin should only be
> called from DCOP::sweep in case !_cont. (sorry, i haven't
> checked for side effects a lot).

True.  It should call tr_restore instead in that case.

Code in tran is correct.

Here is fixed code for s_dc.cc

/*--------------------------------------------------------------------------*/
void DCOP::sweep()
{
  head(_start[0], _stop[0], " ");
  _sim->_bypass_ok = false;
  _sim->set_inc_mode_bad();
  if (_cont) {
    _sim->restore_voltages();
    CARD_LIST::card_list.tr_restore();
  }else{
    _sim->clear_limit();
    CARD_LIST::card_list.tr_begin();
  }
  sweep_recursive(_n_sweeps);
}
/*--------------------------------------------------------------------------*/

new test file:   d_switch.v.cont.ckt
'
V1   1  0  dc 1. ac  1. 
R1   1  2  1.K
S1   2  0  3  0  sss 
V2   3  0  pwl( 0.  0.  5.  5.  15. -5.  25.  5. ) 
.model  sss  sw  ( vt= 0.  vh= 2.  ron= 1.K  roff= 1.E+12 )
.print dc v(nodes) ev(s1) 
.print tran v(nodes) ev(s1) 
.print ac v(nodes) ev(s1) 
.dc v2 -5 0 1
.dc v2 0 5 1 cont
.dc v2 5 0 -1 cont
.dc v2 0 -5 -1 cont
.ac 1k
.tran 0 25 1 
.ac 1k 
.list
.end