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Added a comment in NIiter

This commit is contained in:
Francesco Lannutti 2020-08-25 19:10:23 +02:00
parent 919ace8d8c
commit 82eb9ef996
1 changed files with 13 additions and 0 deletions
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13
src/maths/ni/niiter.c
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@ -136,6 +136,13 @@ NIiter(CKTcircuit *ckt, int maxIter)
#ifdef KLU #ifdef KLU
if (error == E_SINGULAR) { if (error == E_SINGULAR) {
/* Francesco Lannutti - 25 Aug 2020
* If the matrix is numerically singular during ReFactorization, take the same matrix and factor it from scratch in the same iteration.
* This is my mod with KLU. It saves run-time, but also the system at the next iteration may be different.
* How do we guarantee that the system is the same at the next iteration? So, the original SPARSE version below sounds like a bug.
*/
fprintf (stderr, "Warning: KLU ReFactor failed. Factoring again...\n") ; fprintf (stderr, "Warning: KLU ReFactor failed. Factoring again...\n") ;
ckt->CKTniState |= NISHOULDREORDER; ckt->CKTniState |= NISHOULDREORDER;
error = SMPreorder(ckt->CKTmatrix, ckt->CKTpivotAbsTol, ckt->CKTpivotRelTol, ckt->CKTdiagGmin); error = SMPreorder(ckt->CKTmatrix, ckt->CKTpivotAbsTol, ckt->CKTpivotRelTol, ckt->CKTdiagGmin);
@ -158,6 +165,12 @@ NIiter(CKTcircuit *ckt, int maxIter)
#else #else
if (error) { if (error) {
if (error == E_SINGULAR) { if (error == E_SINGULAR) {
/* Francesco Lannutti - 25 Aug 2020
* If the matrix is numerically singular during ReFactorization, factor it from scratch at the next iteration.
* This is the original SPICE3F5 code and uses SPARSE.
*/
ckt->CKTniState |= NISHOULDREORDER; ckt->CKTniState |= NISHOULDREORDER;
DEBUGMSG(" forced reordering....\n"); DEBUGMSG(" forced reordering....\n");
continue; continue;