STATIC void restartPricer(lprec *lp, MYBOOL isdual)
{
REAL *sEdge, seNorm, hold;
int i, j, m;
MYBOOL isDEVEX;
if(!applyPricer(lp))
return;
/* Store the active/current pricing type */
if(isdual == AUTOMATIC)
isdual = (MYBOOL) lp->edgeVector[0];
else
lp->edgeVector[0] = isdual;
m = lp->rows;
/* Determine strategy and check if we have strategy fallback for the primal */
isDEVEX = is_piv_rule(lp, PRICER_DEVEX);
if(!isDEVEX && !isdual)
isDEVEX = is_piv_mode(lp, PRICE_PRIMALFALLBACK);
/* Check if we only need to do the simple DEVEX initialization */
if(isDEVEX && !DEVEX_ENHANCED) {
if(isdual) {
for(i = 1; i <= m; i++)
lp->edgeVector[lp->var_basic[i]] = 1.0;
}
else {
for(i = 1; i <= lp->sum; i++)
if(!lp->is_basic[i])
lp->edgeVector[i] = 1.0;
}
return;
}
/* Otherwise do the full Steepest Edge norm initialization */
sEdge = (REAL *) malloc((m + 1) * sizeof(*sEdge));
if(isdual) {
/* Extract the rows of the basis inverse and compute their squared norms */
for(i = 1; i <= m; i++) {
bsolve(lp, i, sEdge, NULL, 0, 0.0);
/* Compute the edge norm */
seNorm = 0;
for(j = 1; j <= m; j++) {
hold = sEdge[j];
seNorm += hold*hold;
}
j = lp->var_basic[i];
lp->edgeVector[j] = seNorm;
}
}
else {
/* Solve a=Bb for b over all non-basic variables and compute their squared norms */
for(i = 1; i <= lp->sum; i++) {
if(lp->is_basic[i])
continue;
fsolve(lp, i, sEdge, NULL, 0, 0.0, FALSE);
/* Compute the edge norm */
seNorm = 1;
for(j = 1; j <= m; j++) {
hold = sEdge[j];
seNorm += hold*hold;
}
lp->edgeVector[i] = seNorm;
}
}
free(sEdge);
}
STATIC void updatePricer(lprec *lp, int rownr, int colnr, REAL *pcol, REAL *prow, int *nzprow)
{
REAL *vEdge = NULL, cEdge, hold, *newEdge, *w = NULL;
int i, m, n, exitcol, errlevel = DETAILED;
MYBOOL forceRefresh = FALSE, isDual, isDEVEX;
if(!applyPricer(lp))
return;
/* Make sure we have something to update */
hold = lp->edgeVector[0];
if(hold < 0)
return;
isDual = (MYBOOL) (hold > 0);
/* Do common initializations and computations */
m = lp->rows;
n = lp->sum;
isDEVEX = is_piv_rule(lp, PRICER_DEVEX);
exitcol = lp->var_basic[rownr];
/* Solve/copy Bw = a */
/* formWeights(lp, colnr, NULL, &w); Experimental */
formWeights(lp, colnr, pcol, &w);
/* Price norms for the dual simplex - the basic columns */
if(isDual) {
REAL rw;
int targetcol;
/* Don't need to compute cross-products with DEVEX */
if(!isDEVEX) {
allocREAL(lp, &vEdge, m+1, FALSE);
/* Extract the row of the inverse containing the leaving variable
and then form the dot products against the other variables, i.e. "Tau" */
#if 0 /* Extract row explicitly */
bsolve(lp, rownr, vEdge, 0, 0.0);
#else /* Reuse previously extracted row data */
MEMCOPY(vEdge, prow, m+1);
vEdge[0] = 0;
#endif
lp->bfp_ftran_normal(lp, vEdge, NULL);
}
/* Deal with the variable entering the basis to become a new leaving candidate */
cEdge = lp->edgeVector[exitcol];
rw = w[rownr];
hold = 1 / rw;
lp->edgeVector[colnr] = (hold*hold) * cEdge;
/* Possibly adjust initial value in case of Devex */
if(isDEVEX && !DEVEX_ENHANCED && (lp->edgeVector[colnr] < DEVEX_MINVALUE))
lp->edgeVector[colnr] = DEVEX_MINVALUE;
#ifdef Paranoia
if(lp->edgeVector[colnr] <= lp->epsmachine)
report(lp, errlevel, "updatePricer: Invalid dual norm %g at entering index %d - iteration %d\n",
lp->edgeVector[colnr], rownr, lp->total_iter+lp->current_iter);
#endif
/* Then loop over all basic variables, but skip the leaving row */
for(i = 1; i <= m; i++) {
if(i == rownr)
continue;
targetcol = lp->var_basic[i];
hold = w[i];
if(hold == 0)
continue;
hold /= rw;
if(fabs(hold) < lp->epsmachine)
continue;
newEdge = &(lp->edgeVector[targetcol]);
*newEdge += (hold*hold) * cEdge;
if(isDEVEX) {
if((*newEdge) > DEVEX_RESTARTLIMIT) {
forceRefresh = TRUE;
break;
}
}
else {
*newEdge -= 2*hold*vEdge[i];
#ifdef xxApplySteepestEdgeMinimum
*newEdge = my_max(*newEdge, hold*hold+1); /* Kludge; use the primal lower bound */
#else
if(*newEdge <= 0) {
report(lp, errlevel, "updatePricer: Invalid dual norm %g at index %d - iteration %d\n",
*newEdge, i, lp->total_iter+lp->current_iter);
forceRefresh = TRUE;
break;
}
#endif
}
}
}
/* Price norms for the primal simplex - the non-basic columns */
else {
REAL *vTemp, *vAlpha, cAlpha;
int *coltarget;
allocREAL(lp, &vTemp, m+1, TRUE);
allocREAL(lp, &vAlpha, n+1, TRUE);
/* Check if we have strategy fallback for the primal */
if(!isDEVEX)
isDEVEX = is_piv_mode(lp, PRICE_PRIMALFALLBACK);
/* Initialize column target array */
coltarget = (int *) mempool_obtainVector(lp->workarrays, lp->sum+1, sizeof(*coltarget));
if(!get_colIndexA(lp, SCAN_ALLVARS+USE_NONBASICVARS, coltarget, FALSE)) {
mempool_releaseVector(lp->workarrays, (char *) coltarget, FALSE);
return;
}
/* Don't need to compute cross-products with DEVEX */
if(!isDEVEX) {
vEdge = (REAL *) calloc((n + 1), sizeof(*vEdge));
/* Compute v and then N'v */
MEMCOPY(vTemp, w, m+1);
bsolve(lp, -1, vTemp, NULL, lp->epsmachine*DOUBLEROUND, 0.0);
vTemp[0] = 0;
prod_xA(lp, coltarget, vTemp, NULL, XRESULT_FREE, lp->epsmachine, 0.0,
vEdge, NULL);
}
/* Compute Sigma and then Alpha */
bsolve(lp, rownr, vTemp, NULL, 0*DOUBLEROUND, 0.0);
vTemp[0] = 0;
prod_xA(lp, coltarget, vTemp, NULL, XRESULT_FREE, lp->epsmachine, 0.0,
vAlpha, NULL);
mempool_releaseVector(lp->workarrays, (char *) coltarget, FALSE);
/* Update the squared steepest edge norms; first store some constants */
cEdge = lp->edgeVector[colnr];
cAlpha = vAlpha[colnr];
/* Deal with the variable leaving the basis to become a new entry candidate */
hold = 1 / cAlpha;
lp->edgeVector[exitcol] = (hold*hold) * cEdge;
/* Possibly adjust initial value in case of Devex */
if(isDEVEX && !DEVEX_ENHANCED && (lp->edgeVector[exitcol] < DEVEX_MINVALUE))
lp->edgeVector[exitcol] = DEVEX_MINVALUE;
#ifdef Paranoia
if(lp->edgeVector[exitcol] <= lp->epsmachine)
report(lp, errlevel, "updatePricer: Invalid primal norm %g at leaving index %d - iteration %d\n",
lp->edgeVector[exitcol], exitcol, lp->total_iter+lp->current_iter);
#endif
/* Then loop over all non-basic variables, but skip the entering column */
for(i = 1; i <= lp->sum; i++) {
if(lp->is_basic[i] || (i == colnr))
continue;
hold = vAlpha[i];
if(hold == 0)
continue;
hold /= cAlpha;
if(fabs(hold) < lp->epsmachine)
continue;
newEdge = &(lp->edgeVector[i]);
*newEdge += (hold*hold) * cEdge;
if(isDEVEX) {
if((*newEdge) > DEVEX_RESTARTLIMIT) {
forceRefresh = TRUE;
break;
}
}
else {
*newEdge -= 2*hold*vEdge[i];
#ifdef ApplySteepestEdgeMinimum
*newEdge = my_max(*newEdge, hold*hold+1);
#else
if(*newEdge < 0) {
report(lp, errlevel, "updatePricer: Invalid primal norm %g at index %d - iteration %d\n",
*newEdge, i, lp->total_iter+lp->current_iter);
if(lp->spx_trace)
report(lp, errlevel, "Error detail: (RelAlpha=%g, vEdge=%g, cEdge=%g)\n", hold, vEdge[i], cEdge);
forceRefresh = TRUE;
break;
}
#endif
}
}
FREE(vAlpha);
FREE(vTemp);
}
if(vEdge != NULL)
FREE(vEdge);
freeWeights(w);
if(forceRefresh)
restartPricer(lp, AUTOMATIC);
}
STATIC MYBOOL restartPricer(lprec *lp, MYBOOL isdual)
{
REAL *sEdge = NULL, seNorm, hold;
int i, j, m;
MYBOOL isDEVEX, ok = applyPricer(lp);
/* Correction from V6, apparently, via Kjell Eikland and the
** lpSolve mailing list 2014-06-18 2:57 p.m. */
if (ok && (lp->edgeVector[0] < 0) && (isdual == AUTOMATIC))
ok = FALSE;
if(!ok)
return( ok );
/* Store the active/current pricing type */
if(isdual == AUTOMATIC)
isdual = (MYBOOL) lp->edgeVector[0];
else
lp->edgeVector[0] = isdual;
m = lp->rows;
/* Determine strategy and check if we have strategy fallback for the primal */
isDEVEX = is_piv_rule(lp, PRICER_DEVEX);
if(!isDEVEX && !isdual)
isDEVEX = is_piv_mode(lp, PRICE_PRIMALFALLBACK);
/* Check if we only need to do the simple DEVEX initialization */
if(!is_piv_mode(lp, PRICE_TRUENORMINIT)) {
if(isdual) {
for(i = 1; i <= m; i++)
lp->edgeVector[lp->var_basic[i]] = 1.0;
}
else {
for(i = 1; i <= lp->sum; i++)
if(!lp->is_basic[i])
lp->edgeVector[i] = 1.0;
}
return( ok );
}
/* Otherwise do the full Steepest Edge norm initialization */
ok = allocREAL(lp, &sEdge, m+1, FALSE);
if(!ok)
return( ok );
if(isdual) {
/* Extract the rows of the basis inverse and compute their squared norms */
for(i = 1; i <= m; i++) {
bsolve(lp, i, sEdge, NULL, 0, 0.0);
/* Compute the edge norm */
seNorm = 0;
for(j = 1; j <= m; j++) {
hold = sEdge[j];
seNorm += hold*hold;
}
j = lp->var_basic[i];
lp->edgeVector[j] = seNorm;
}
}
else {
/* Solve a=Bb for b over all non-basic variables and compute their squared norms */
for(i = 1; i <= lp->sum; i++) {
if(lp->is_basic[i])
continue;
fsolve(lp, i, sEdge, NULL, 0, 0.0, FALSE);
/* Compute the edge norm */
seNorm = 1;
for(j = 1; j <= m; j++) {
hold = sEdge[j];
seNorm += hold*hold;
}
lp->edgeVector[i] = seNorm;
}
}
FREE(sEdge);
return( ok );
}
