Re: [ng-spice] Pole-zero analysis (and others)
On Sat, Jun 10, 2000 at 09:33:21PM +0200, Arno W. Peters wrote:
> Stack backtrace is as follows:
>
> #0 0x808dd77 in alter ()
> #1 0x808c4ef in CKTpzRunTrial ()
> #2 0x808b196 in CKTpzFindZeros ()
> #3 0x8089ad3 in PZan (ckt=0x80ff408, reset=1) at pzan.c:59
> #4 0x807e6b5 in CKTdoJob (inCkt=0x80ff408, reset=1, inTask=0x80ff770)
> at cktdojob.c:130
> #5 0x806e5f0 in if_run (t=0x80ff408 "", what=0x80b6889 "run",
>args=0x8100200,
> tab=0x80ff390) at spiceif.c:188
> #6 0x806badb in dosim (what=0x80b6889 "run", wl=0x0) at runcoms.c:237
> #7 0x806bbc7 in ft_dorun (file=0x0) at runcoms.c:275
> #8 0x8053843 in main (argc=1, argv=0xbffff974) at ./main.c:619
>
> I have not yet been able to determine the cause of this segfault.
Update: This crash was because I enabled PZDEBUG and the code tried to
dereference a NULL pointer and print the result.
The results of the modified circuit are:
Multistage filter
---------------------------------------------------------------------
Index pole(1) pole(2)
---------------------------------------------------------------------
0 -5.500000e+07, 0.000000e+00 -1.000000e+08, 1.833176e-301
^L
Multistage filter
---------------------------------------------------------------------
Index pole(3)
---------------------------------------------------------------------
0 -1.000000e+08, -1.833176e-301
Three poles for a first order circuit?
Regards,
--
Arno
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Partial thread listing:
- Re: [ng-spice] Pole-zero analysis (and others), (continued)
Additional sample netlists requested
Arno W. Peters