/********** Copyright 1990 Regents of the University of California. All rights reserved. Author: 1985 Thomas L. Quarles Modified: 2001 AlansFixes **********/ /* * NIiter(ckt,maxIter) * * This subroutine performs the actual numerical iteration. * It uses the sparse matrix stored in the circuit struct * along with the matrix loading program, the load data, the * convergence test function, and the convergence parameters */ #include "ngspice/ngspice.h" #include "ngspice/trandefs.h" #include "ngspice/cktdefs.h" #include "ngspice/smpdefs.h" #include "ngspice/sperror.h" /* NIiter() - return value is non-zero for convergence failure */ int NIiter(CKTcircuit *ckt, int maxIter) { int iterno; int ipass; int error; int i,j; /* temporaries for finding error location */ double *temp; double startTime; static char *msg = "Too many iterations without convergence"; CKTnode *node; /* current matrix entry */ double diff, maxdiff, damp_factor, *OldCKTstate0=NULL; if ( maxIter < 100 ) maxIter = 100; /* some convergence issues that get resolved by increasing max iter */ iterno=0; ipass=0; if( (ckt->CKTmode & MODETRANOP) && (ckt->CKTmode & MODEUIC)) { temp = ckt->CKTrhsOld; ckt->CKTrhsOld = ckt->CKTrhs; ckt->CKTrhs = temp; error = CKTload(ckt); if(error) { return(error); } return(OK); } #ifdef WANT_SENSE2 if(ckt->CKTsenInfo) { error = NIsenReinit(ckt); if(error) return(error); } #endif if(ckt->CKTniState & NIUNINITIALIZED) { error = NIreinit(ckt); if(error) { #ifdef STEPDEBUG printf("re-init returned error \n"); #endif return(error); } } /* OldCKTstate0=TMALLOC(double, ckt->CKTnumStates + 1); */ for(;;) { ckt->CKTnoncon=0; #ifdef NEWPRED if(!(ckt->CKTmode & MODEINITPRED)) { #else /* NEWPRED */ if(1) { /* } */ #endif /* NEWPRED */ error = CKTload(ckt); /*printf("loaded, noncon is %d\n",ckt->CKTnoncon);*/ /*fflush(stdout);*/ iterno++; if(error) { ckt->CKTstat->STATnumIter += iterno; #ifdef STEPDEBUG printf("load returned error \n"); #endif FREE(OldCKTstate0); return(error); } /*printf("after loading, before solving\n");*/ /*CKTdump(ckt);*/ if(!(ckt->CKTniState & NIDIDPREORDER)) { error = SMPpreOrder(ckt->CKTmatrix); if(error) { ckt->CKTstat->STATnumIter += iterno; #ifdef STEPDEBUG printf("pre-order returned error \n"); #endif FREE(OldCKTstate0); return(error); /* badly formed matrix */ } ckt->CKTniState |= NIDIDPREORDER; } if( (ckt->CKTmode & MODEINITJCT) || ( (ckt->CKTmode & MODEINITTRAN) && (iterno==1))) { ckt->CKTniState |= NISHOULDREORDER; } if(ckt->CKTniState & NISHOULDREORDER) { startTime = SPfrontEnd->IFseconds(); error = SMPreorder(ckt->CKTmatrix,ckt->CKTpivotAbsTol, ckt->CKTpivotRelTol,ckt->CKTdiagGmin); ckt->CKTstat->STATreorderTime += SPfrontEnd->IFseconds() - startTime; if(error) { /* new feature - we can now find out something about what is * wrong - so we ask for the troublesome entry */ SMPgetError(ckt->CKTmatrix,&i,&j); SPfrontEnd->IFerrorf (ERR_WARNING, "singular matrix: check nodes %s and %s\n", NODENAME(ckt,i), NODENAME(ckt,j)); ckt->CKTstat->STATnumIter += iterno; #ifdef STEPDEBUG printf("reorder returned error \n"); #endif FREE(OldCKTstate0); return(error); /* can't handle these errors - pass up! */ } ckt->CKTniState &= ~NISHOULDREORDER; } else { startTime = SPfrontEnd->IFseconds(); error=SMPluFac(ckt->CKTmatrix,ckt->CKTpivotAbsTol, ckt->CKTdiagGmin); ckt->CKTstat->STATdecompTime += SPfrontEnd->IFseconds() - startTime; if(error) { if( error == E_SINGULAR ) { ckt->CKTniState |= NISHOULDREORDER; DEBUGMSG(" forced reordering....\n"); continue; } /*CKTload(ckt);*/ /*SMPprint(ckt->CKTmatrix,stdout);*/ /* seems to be singular - pass the bad news up */ ckt->CKTstat->STATnumIter += iterno; #ifdef STEPDEBUG printf("lufac returned error \n"); #endif FREE(OldCKTstate0); return(error); } } /*moved it to here as if xspice is included then CKTload changes CKTnumStates the first time it is run */ if(!OldCKTstate0) OldCKTstate0=TMALLOC(double, ckt->CKTnumStates + 1); for(i=0; iCKTnumStates; i++) { OldCKTstate0[i] = ckt->CKTstate0[i]; } startTime = SPfrontEnd->IFseconds(); SMPsolve(ckt->CKTmatrix,ckt->CKTrhs,ckt->CKTrhsSpare); ckt->CKTstat->STATsolveTime += SPfrontEnd->IFseconds() - startTime; #ifdef STEPDEBUG /*XXXX*/ if (*ckt->CKTrhs != 0.0) printf("NIiter: CKTrhs[0] = %g\n", *ckt->CKTrhs); if (*ckt->CKTrhsSpare != 0.0) printf("NIiter: CKTrhsSpare[0] = %g\n", *ckt->CKTrhsSpare); if (*ckt->CKTrhsOld != 0.0) printf("NIiter: CKTrhsOld[0] = %g\n", *ckt->CKTrhsOld); /*XXXX*/ #endif *ckt->CKTrhs = 0; *ckt->CKTrhsSpare = 0; *ckt->CKTrhsOld = 0; if(iterno > maxIter) { /*fprintf(stderr,"too many iterations without convergence: %d iter's (max iter == %d)\n", iterno,maxIter);*/ ckt->CKTstat->STATnumIter += iterno; FREE(errMsg); errMsg = TMALLOC(char, strlen(msg) + 1); strcpy(errMsg,msg); #ifdef STEPDEBUG printf("iterlim exceeded \n"); #endif FREE(OldCKTstate0); return(E_ITERLIM); } if(ckt->CKTnoncon==0 && iterno!=1) { ckt->CKTnoncon = NIconvTest(ckt); } else { ckt->CKTnoncon = 1; } #ifdef STEPDEBUG printf("noncon is %d\n",ckt->CKTnoncon); #endif } if( (ckt->CKTnodeDamping!=0) && (ckt->CKTnoncon!=0) && ((ckt->CKTmode & MODETRANOP) || (ckt->CKTmode & MODEDCOP)) && (iterno>1) ) { maxdiff=0; for (node = ckt->CKTnodes->next; node; node = node->next) { if(node->type == SP_VOLTAGE) { diff = ckt->CKTrhs [node->number] - ckt->CKTrhsOld [node->number]; if (diff>maxdiff) maxdiff=diff; } } if (maxdiff>10) { damp_factor=10/maxdiff; if (damp_factor<0.1) damp_factor=0.1; for (node = ckt->CKTnodes->next; node; node = node->next) { diff = ckt->CKTrhs[node->number] - ckt->CKTrhsOld[node->number]; ckt->CKTrhs[node->number] = ckt->CKTrhsOld[node->number] + (damp_factor * diff); } for(i=0; iCKTnumStates; i++) { diff = ckt->CKTstate0[i] - OldCKTstate0[i]; ckt->CKTstate0[i] = OldCKTstate0[i] + (damp_factor * diff); } } } if(ckt->CKTmode & MODEINITFLOAT) { if ((ckt->CKTmode & MODEDC) && ( ckt->CKThadNodeset) ) { if(ipass) { ckt->CKTnoncon=ipass; } ipass=0; } if(ckt->CKTnoncon == 0) { ckt->CKTstat->STATnumIter += iterno; FREE(OldCKTstate0); return(OK); } } else if(ckt->CKTmode & MODEINITJCT) { ckt->CKTmode = (ckt->CKTmode&(~INITF))|MODEINITFIX; ckt->CKTniState |= NISHOULDREORDER; } else if (ckt->CKTmode & MODEINITFIX) { if(ckt->CKTnoncon==0) ckt->CKTmode = (ckt->CKTmode&(~INITF))|MODEINITFLOAT; ipass=1; } else if (ckt->CKTmode & MODEINITSMSIG) { ckt->CKTmode = (ckt->CKTmode&(~INITF))|MODEINITFLOAT; } else if (ckt->CKTmode & MODEINITTRAN) { if(iterno<=1) ckt->CKTniState |= NISHOULDREORDER; ckt->CKTmode = (ckt->CKTmode&(~INITF))|MODEINITFLOAT; } else if (ckt->CKTmode & MODEINITPRED) { ckt->CKTmode = (ckt->CKTmode&(~INITF))|MODEINITFLOAT; } else { ckt->CKTstat->STATnumIter += iterno; #ifdef STEPDEBUG printf("bad initf state \n"); #endif FREE(OldCKTstate0); return(E_INTERN); /* impossible - no such INITF flag! */ } /* build up the lvnim1 array from the lvn array */ temp = ckt->CKTrhsOld; ckt->CKTrhsOld = ckt->CKTrhs; ckt->CKTrhs = temp; /*printf("after loading, after solving\n");*/ /*CKTdump(ckt);*/ } /*NOTREACHED*/ }