dyret_enum dy_warmstart (lpprob_struct *orig_lp)
/*
This routine is responsible for recreating the active constraint system,
basis, and status specified by the user in orig_lp. It will handle even the
pathological case of 0 active constraints and 0 active variables. If the
user has supplied an active variable vector, only those variables will be
activated. Clearly, the supplied basis, status, and active variable vector
should be consistent, or bad things will happen.
If we're operating in fullsys mode, we need to check here for additions to
the constraint system.
<< In the very near future, this routine should also be upgraded to cope
with the possibility that constraints specified in the warm start basis
have disappeared. >>
Parameters:
orig_lp: The original lp problem structure
Returns: dyrOK if the setup completes without error, any of a number of
error codes otherwise (dyrFATAL, dyrINV, or a code from dy_factor)
*/
{ int vndx,dyvndx,bpos,cndx,dycndx,dycsze,dyvsze,nbfxcnt ;
double *vlb,*vub,vlbj,vubj,obj ;
consys_struct *orig_sys ;
flags *orig_status,vstat,calcflgs ;
dyret_enum retval ;
basisel_struct *orig_basis ;
bool *orig_actvars,rngseen,noactvarspec ;
pkvec_struct *pkcol ;
char nmebuf[50] ;
flags parts = CONSYS_OBJ|CONSYS_VUB|CONSYS_VLB|CONSYS_RHS|CONSYS_RHSLOW|
CONSYS_VTYP|CONSYS_CTYP,
opts = CONSYS_LVARS|CONSYS_WRNATT ;
const char *rtnnme = "dy_warmstart" ;
extern void dy_setfinalstatus(void) ; /* dy_hotstart.c */
# if defined(DYLP_PARANOIA) || !defined(DYLP_NDEBUG)
double xi ;
# endif
retval = dyrINV ;
nbfxcnt = -1 ;
/*
Do a little unpacking.
*/
orig_sys = orig_lp->consys ;
orig_status = orig_lp->status ;
orig_basis = orig_lp->basis->el ;
if (flgon(orig_lp->ctlopts,lpctlACTVARSIN) && dy_opts->fullsys == FALSE)
{ orig_actvars = orig_lp->actvars ;
noactvarspec = FALSE ; }
else
{ orig_actvars = NULL ;
noactvarspec = TRUE ; }
/*
Initialise the statistics on loadable/unloadable variables and constraints.
*/
dy_lp->sys.forcedfull = FALSE ;
dy_lp->sys.vars.loadable = orig_sys->varcnt ;
dy_lp->sys.vars.unloadable = 0 ;
dy_lp->sys.cons.loadable = orig_sys->concnt ;
dy_lp->sys.cons.unloadable = 0 ;
/*
Create the dy_sys constraint system to match the user's basis and active
variables (if specified). We'll create the system with logicals enabled.
For variables, if there is an active variable vector, skim it for a count.
Otherwise, skim the status array and count the number of nonbasic fixed
variables (which will never become active).
For constraints, we need to consider the possibility that the user has
added cuts and is trusting dylp to deal with it. If we're operating in the
usual dynamic mode, this will be picked up automatically, and we can size
the constraint system to the active constraints of the basis. But if we're
operating in fullsys mode, we need to add them here. In this case, the
number of constraints is the current size of the constraint system.
Take this opportunity to clean the bounds arrays, making sure that bounds
within the feasibility tolerance of one another are set to be exactly
equal. (This simplifies handling fixed variables.) For nonbasic variables,
force the status to NBFX and cancel activation if actvars is present. Basic
variables which need BFX are picked up later, after the basis is
established.
*/
vub = orig_sys->vub ;
vlb = orig_sys->vlb ;
dyio_outfxd(nmebuf,-((int) (sizeof(nmebuf)-1)),
'l',"%s[actv]",orig_sys->nme) ;
if (noactvarspec == FALSE)
{ dyvsze = 0 ;
for (vndx = 1 ; vndx <= orig_sys->varcnt ; vndx++)
{ vlbj = vlb[vndx] ;
vubj = vub[vndx] ;
if (atbnd(vlbj,vubj))
{ if (vlbj != vubj)
{
# ifndef DYLP_NDEBUG
if (dy_opts->print.setup >= 3)
{ dyio_outfmt(dy_logchn,dy_gtxecho,
"\n\tForcing equal bound %g for %s (%d)",
(vlbj+vubj)/2,consys_nme(orig_sys,'v',vndx,0,0),vndx) ;
dyio_outfmt(dy_logchn,dy_gtxecho,
"\n\t original lb = %g, ub = %g, diff = %g, tol = %g",
vlbj,vubj,vubj-vlbj,dy_tols->pfeas) ; }
# endif
vlb[vndx] = (vlbj+vubj)/2 ;
vub[vndx] = vlb[vndx] ; }
if (((int) orig_status[vndx]) > 0)
{ orig_status[vndx] = vstatNBFX ;
orig_actvars[vndx] = FALSE ; } }
if (vlb[vndx] > vub[vndx])
{ dy_lp->lpret = lpINFEAS ;
# ifndef DYLP_NDEBUG
if (dy_opts->print.setup >= 1)
{ dyio_outfmt(dy_logchn,dy_gtxecho,
"\n\tTrivial infeasibility for %s (%d), lb = %g > ub = %g.",
consys_nme(orig_sys,'v',vndx,0,0),vndx,vlb[vndx],vub[vndx]) ; }
# endif
}
if (orig_actvars[vndx] == TRUE) dyvsze++ ; } }
else
{ nbfxcnt = 0 ;
for (vndx = 1 ; vndx <= orig_sys->varcnt ; vndx++)
{ vlbj = vlb[vndx] ;
vubj = vub[vndx] ;
if (atbnd(vlbj,vubj))
{ if (vlbj != vubj)
{
# ifndef DYLP_NDEBUG
if (dy_opts->print.setup >= 3)
{ dyio_outfmt(dy_logchn,dy_gtxecho,
"\n\tForcing equal bound %g for %s (g)",
(vlbj+vubj)/2,consys_nme(orig_sys,'v',vndx,0,0),vndx) ;
dyio_outfmt(dy_logchn,dy_gtxecho,
"\n\t original lb = %g, ub = %g, diff = %g, tol = %g",
vlbj,vubj,vubj-vlbj,dy_tols->pfeas) ; }
# endif
vlb[vndx] = (vlbj+vubj)/2 ;
vub[vndx] = vlb[vndx] ; }
if (((int) orig_status[vndx]) > 0)
{ orig_status[vndx] = vstatNBFX ; } }
if (vlb[vndx] > vub[vndx])
{ dy_lp->lpret = lpINFEAS ; }
if ((((int) orig_status[vndx]) > 0) &&
flgon(orig_status[vndx],vstatNBFX))
{ nbfxcnt++ ; } }
dyvsze = orig_sys->varcnt-nbfxcnt ; }
if (dy_opts->fullsys == TRUE)
dycsze = orig_sys->concnt ;
else
dycsze = orig_lp->basis->len ;
dyvsze += dycsze ;
# ifndef DYLP_NDEBUG
if (dy_opts->print.setup >= 1)
{ dyio_outfmt(dy_logchn,dy_gtxecho,
"\n creating constraint system %s (%d x %d+%d)",
nmebuf,dycsze,dyvsze-dycsze,dycsze) ;
if (dy_opts->print.setup >= 3)
{ if (flgoff(orig_lp->ctlopts,lpctlACTVARSIN))
dyio_outfmt(dy_logchn,dy_gtxecho,
"\n %d nonbasic fixed variables excluded.",
nbfxcnt) ; } }
# endif
dy_sys = consys_create(nmebuf,parts,opts,dycsze,dyvsze,dy_tols->inf) ;
if (dy_sys == NULL)
{ errmsg(152,rtnnme,nmebuf) ;
return (dyrFATAL) ; }
/*
Hang a set of translation vectors onto each system: origcons and origvars
on orig_sys, and actcons and actvars on dy_sys.
*/
if (consys_attach(dy_sys,CONSYS_ROW,
sizeof(int),(void **) &dy_actvars) == FALSE)
{ errmsg(100,rtnnme,dy_sys->nme,"active -> original variable map") ;
return (dyrFATAL) ; }
if (consys_attach(dy_sys,CONSYS_COL,
sizeof(int),(void **) &dy_actcons) == FALSE)
{ errmsg(100,rtnnme,dy_sys->nme,"active -> original constraint map") ;
return (dyrFATAL) ; }
if (consys_attach(orig_sys,CONSYS_ROW,
sizeof(int),(void **) &dy_origvars) == FALSE)
{ errmsg(100,rtnnme,orig_sys->nme,"original -> active variable map") ;
return (dyrFATAL) ; }
if (consys_attach(orig_sys,CONSYS_COL,
sizeof(int),(void **) &dy_origcons) == FALSE)
{ errmsg(100,rtnnme,orig_sys->nme,"original -> active constraint map") ;
return (dyrFATAL) ; }
/*
dy_origvars is cleared to 0 as it's attached, indicating that the original
variables have no predefined status. We need to correct this.
If the caller's supplied an active variable vector, we can use it to
activate variables prior to adding constraints. (But in any case don't
activate nonbasic fixed variables.) It's illegal to declare a formerly
basic variable to be inactive by the simple expedient of setting
actvars[vndx] = FALSE, hence the paranoid check.
Otherwise, we'll need to depend on dy_loadcon to activate the variables
referenced in the active constraints. We'll still fill in origvars, with
two purposes:
* We can avoid activating nonbasic fixed variables.
* We can use dy_origvars == 0 as a paranoid check from here on out.
Inactive variables are required to be nonbasic, so in this case the proper
status for formerly basic variables is SB.
*/
if (noactvarspec == FALSE)
{
# ifndef DYLP_NDEBUG
if (dy_opts->print.setup >= 1)
{ dyio_outfmt(dy_logchn,dy_gtxecho,
"\n processing active variable list ...") ; }
# endif
pkcol = pkvec_new(0) ;
for (vndx = 1 ; vndx <= orig_sys->varcnt ; vndx++)
{ if (((int) orig_status[vndx]) > 0)
vstat = orig_status[vndx] ;
else
vstat = vstatB ;
if (orig_actvars[vndx] == TRUE && flgoff(vstat,vstatNBFX))
{ if (consys_getcol_pk(orig_sys,vndx,&pkcol) == FALSE)
{ errmsg(122,rtnnme,orig_sys->nme,"variable",
consys_nme(orig_sys,'v',vndx,TRUE,NULL),vndx) ;
retval = dyrFATAL ;
break ; }
if (consys_addcol_pk(dy_sys,vartypCON,pkcol,
orig_sys->obj[vndx],vlb[vndx],vub[vndx]) == FALSE)
{ errmsg(156,rtnnme,"variable",dy_sys->nme,pkcol->nme) ;
retval = dyrFATAL ;
break ; }
dyvndx = pkcol->ndx ;
dy_origvars[vndx] = dyvndx ;
dy_actvars[dyvndx] = vndx ;
# ifndef DYLP_NDEBUG
if (dy_opts->print.setup >= 3)
{ dyio_outfmt(dy_logchn,dy_gtxecho,
"\n\tactivating %s variable %s (%d) to index %d.",
consys_prtvartyp(orig_sys->vtyp[vndx]),
consys_nme(orig_sys,'v',vndx,FALSE,NULL),vndx,dyvndx) ; }
# endif
}
else
{
# ifdef DYLP_PARANOIA
if (flgon(vstat,vstatBASIC))
{ errmsg(380,rtnnme,orig_sys->nme,
consys_nme(orig_sys,'v',vndx,FALSE,NULL),vndx,
dy_prtvstat(vstat),"non-basic") ;
retval = dyrFATAL ;
break ; }
# endif
dy_origvars[vndx] = -((int) vstat) ; } }
pkvec_free(pkcol) ;
if (retval != dyrINV) return (retval) ; }
else
{ for (vndx = 1 ; vndx <= orig_sys->varcnt ; vndx++)
{ if (((int) orig_status[vndx]) > 0)
vstat = orig_status[vndx] ;
else
vstat = vstatSB ;
MARK_INACTIVE_VAR(vndx,-((int) vstat)) ; } }
/*
Walk the basis and install the constraints in order. When we're finished
with this, the active system will be up and about. In the case where
there's no active variable specification, some of the status information
written into dy_origvars may have been overwritten; only variables with
vstatNBFX are guaranteed to remain inactive.
*/
rngseen = FALSE ;
for (bpos = 1 ; bpos <= orig_lp->basis->len ; bpos++)
{ cndx = orig_basis[bpos].cndx ;
# ifndef DYLP_NDEBUG
if (dy_opts->print.setup >= 2)
dyio_outfmt(dy_logchn,dy_gtxecho,
"\n activating %s %s (%d) in pos'n %d",
consys_prtcontyp(orig_sys->ctyp[cndx]),
consys_nme(orig_sys,'c',cndx,FALSE,NULL),cndx,bpos) ;
# endif
# ifdef DYLP_STATISTICS
if (dy_stats != NULL) dy_stats->cons.init[cndx] = TRUE ;
# endif
if (dy_loadcon(orig_sys,cndx,noactvarspec,NULL) == FALSE)
{ errmsg(430,rtnnme,
dy_sys->nme,dy_prtlpphase(dy_lp->phase,TRUE),dy_lp->tot.iters,
"activate","constraint",
consys_nme(orig_sys,'c',cndx,TRUE,NULL),cndx) ;
return (dyrFATAL) ; }
if (orig_sys->ctyp[cndx] == contypRNG) rngseen = TRUE ; }
/*
If we're in fullsys mode, repeat constraint installation actions for any
cuts added after this basis was assembled.
*/
if (dy_opts->fullsys == TRUE)
{ for (cndx = orig_lp->basis->len+1 ; cndx <= orig_sys->concnt ; cndx++)
{
# ifndef DYLP_NDEBUG
if (dy_opts->print.setup >= 2)
dyio_outfmt(dy_logchn,dy_gtxecho,
"\n activating %s %s (%d) in pos'n %d",
consys_prtcontyp(orig_sys->ctyp[cndx]),
consys_nme(orig_sys,'c',cndx,FALSE,NULL),cndx,cndx) ;
# endif
# ifdef DYLP_STATISTICS
if (dy_stats != NULL) dy_stats->cons.init[cndx] = TRUE ;
# endif
if (dy_loadcon(orig_sys,cndx,noactvarspec,NULL) == FALSE)
{ errmsg(430,rtnnme,
dy_sys->nme,dy_prtlpphase(dy_lp->phase,TRUE),dy_lp->tot.iters,
"activate","constraint",
consys_nme(orig_sys,'c',cndx,TRUE,NULL),cndx) ;
return (dyrFATAL) ; }
if (orig_sys->ctyp[cndx] == contypRNG) rngseen = TRUE ; } }
# ifdef DYLP_PARANOIA
/*
Paranoid checks and informational print statements.
*/
if (dy_chkdysys(orig_sys) == FALSE) return (dyrINV) ;
# endif
# ifndef DYLP_NDEBUG
if (dy_opts->print.setup >= 1)
{ dyio_outfmt(dy_logchn,dy_gtxecho,
"\n system %s has %d constraints, %d+%d variables",
dy_sys->nme,dy_sys->concnt,dy_sys->archvcnt,dy_sys->logvcnt) ;
dyio_outfmt(dy_logchn,dy_gtxecho,
"\n %d constraints, %d variables remain inactive in system %s.",
orig_sys->concnt-dy_sys->concnt,orig_sys->archvcnt-dy_sys->archvcnt,
orig_sys->nme) ;
if (dy_opts->print.setup >= 4)
{ nbfxcnt = 0 ;
for (vndx = 1 ; vndx <= orig_sys->varcnt ; vndx++)
{ if (INACTIVE_VAR(vndx))
{ vstat = (flags) (-dy_origvars[vndx]) ;
switch (getflg(vstat,vstatSTATUS))
{ case vstatNBUB:
{ xi = orig_sys->vub[vndx] ;
break ; }
case vstatNBLB:
case vstatNBFX:
{ xi = orig_sys->vlb[vndx] ;
break ; }
case vstatNBFR:
{ xi = 0 ;
break ; }
default:
{ errmsg(433,rtnnme,dy_sys->nme,
dy_prtlpphase(dy_lp->phase,TRUE),dy_lp->tot.iters,
"inactive",consys_nme(orig_sys,'v',vndx,TRUE,NULL),
vndx,dy_prtvstat(vstat)) ;
return (dyrINV) ; } }
if (xi != 0)
{ if (nbfxcnt == 0)
dyio_outfmt(dy_logchn,dy_gtxecho,
"\n\tinactive variables with nonzero values:") ;
nbfxcnt++ ;
dyio_outfmt(dy_logchn,dy_gtxecho,"\n\t%s (%d) = %g, status %s",
consys_nme(orig_sys,'v',vndx,FALSE,NULL),vndx,xi,
dy_prtvstat(vstat)) ; } } }
if (nbfxcnt == 0)
dyio_outfmt(dy_logchn,dy_gtxecho,
"\n\tall inactive variables are zero.") ; } }
# endif
/*
Time to assemble the basis. Attach the basis and inverse basis vectors to
the constraint system. consys_attach will initialise them to 0.
*/
if (consys_attach(dy_sys,CONSYS_COL,
sizeof(int),(void **) &dy_basis) == FALSE)
{ errmsg(100,rtnnme,dy_sys->nme,"basis vector") ;
return (dyrFATAL) ; }
if (consys_attach(dy_sys,CONSYS_ROW,
sizeof(int),(void **) &dy_var2basis) == FALSE)
{ errmsg(100,rtnnme,dy_sys->nme,"inverse basis vector") ;
return (dyrFATAL) ; }
# ifndef DYLP_NDEBUG
if (dy_opts->print.crash >= 1)
{ if (dy_opts->print.setup == 0)
dyio_outfmt(dy_logchn,dy_gtxecho,
"\n %s: regenerating the basis ...",rtnnme) ;
else
dyio_outfmt(dy_logchn,dy_gtxecho,
"\n regenerating the basis.",rtnnme) ; }
# endif
/*
Load the basis. For variables, we need to translate architecturals using
dy_origvars, and watch out for logicals (vndx = negative of associated
constraint index). After all the paranoia, we finally update dy_basis and
dy_var2basis.
Because we loaded the constraints in the order they were listed in the
basis, we should have that dycndx = bpos, hence dy_actcons[bpos] = cndx.
If we're installing a basic variable, it should be active already. For
architectural variables, the check is made in dy_origvars. For a logical,
the associated constraint should be active, hence a non-zero entry in
dy_origcons. For architecturals, we also check if there are any non-zero
coefficients remaining in the column (who knows what the user has done to
the constraint system). This rates a message if the print level is high
enough, but the basis pacakge is capable of patching the basis. (Indeed,
it's hard to do it correctly here.)
*/
# ifdef DYLP_PARANOIA
pkcol = pkvec_new(0) ;
retval = dyrOK ;
# endif
for (bpos = 1 ; bpos <= orig_lp->basis->len ; bpos++)
{ cndx = orig_basis[bpos].cndx ;
dycndx = dy_origcons[cndx] ;
vndx = orig_basis[bpos].vndx ;
if (vndx < 0)
{ dyvndx = dy_origcons[-vndx] ; }
else
{ dyvndx = dy_origvars[vndx] ; }
# ifdef DYLP_PARANOIA
if (dycndx <= 0)
{ errmsg(369,rtnnme,orig_sys->nme,"constraint",
consys_nme(orig_sys,'c',cndx,FALSE,NULL),cndx,
"cons",cndx,dycndx) ;
retval = dyrINV ;
break ; }
if (dy_actcons[bpos] != cndx)
{ errmsg(370,rtnnme,dy_sys->nme,
consys_nme(orig_sys,'c',cndx,FALSE,NULL),cndx,bpos,
consys_nme(orig_sys,'c',dy_actcons[bpos],FALSE,NULL),
dy_actcons[bpos]) ;
if (dycndx != bpos) { errmsg(1,rtnnme,__LINE__) ; }
retval = dyrINV ;
break ; }
if (vndx < 0)
{ if (dyvndx <= 0)
{ errmsg(369,rtnnme,orig_sys->nme,"constraint",
consys_nme(orig_sys,'c',-vndx,FALSE,NULL),-vndx,
"cons",-vndx,dyvndx) ;
retval = dyrINV ;
break ; } }
else
{ if (dyvndx <= 0)
{ errmsg(369,rtnnme,orig_sys->nme,"variable",
consys_nme(orig_sys,'v',vndx,FALSE,NULL),vndx,
"vars",vndx,dyvndx) ;
retval = dyrINV ;
break ; }
if (consys_getcol_pk(dy_sys,dyvndx,&pkcol) == FALSE)
{ errmsg(122,rtnnme,orig_sys->nme,"variable",
consys_nme(orig_sys,'v',vndx,TRUE,NULL),vndx) ;
retval = dyrFATAL ;
break ; }
if (pkcol->cnt == 0 && dy_opts->print.crash >= 4)
{ dyio_outfmt(dy_logchn,dy_gtxecho,
"\n %s (%d) has no non-zeros in active constraints.",
consys_nme(dy_sys,'v',dyvndx,TRUE,NULL),dyvndx) ; } }
# endif
dy_basis[dycndx] = dyvndx ;
dy_var2basis[dyvndx] = dycndx ; }
/*
If we're in fullsys mode, make the logical basic for any remaining
constraints.
*/
if (dy_opts->fullsys == TRUE)
{ for ( ; bpos <= dy_sys->concnt ; bpos++)
{ dy_basis[bpos] = bpos ;
dy_var2basis[bpos] = bpos ; } }
# ifdef DYLP_PARANOIA
pkvec_free(pkcol) ;
if (retval != dyrOK) return (retval) ;
# endif
# ifndef DYLP_NDEBUG
if (dy_opts->print.crash >= 4)
{ dyio_outfmt(dy_logchn,dy_gtxecho,
"\n\t Pos'n Variable Constraint") ;
for (bpos = 1 ; bpos <= orig_lp->basis->len ; bpos++)
{ vndx = dy_basis[bpos] ;
dyio_outfmt(dy_logchn,dy_gtxecho,"\n\t %3d (%3d) %-15s",bpos,vndx,
consys_nme(dy_sys,'v',vndx,FALSE,NULL)) ;
dyio_outfmt(dy_logchn,dy_gtxecho,"%-15s",
consys_nme(dy_sys,'c',bpos,FALSE,NULL)) ; } }
# endif
/*
Factor the basis. We don't want any of the primal or dual variables
calculated just yet. If this fails we're in deep trouble. Don't do this
if we're dealing with a constraint system with no constraints!
*/
if (dy_sys->concnt > 0)
{
# ifndef DYLP_NDEBUG
if (dy_opts->print.crash >= 2)
dyio_outfmt(dy_logchn,dy_gtxecho,"\n factoring ...") ;
# endif
calcflgs = 0 ;
retval = dy_factor(&calcflgs) ;
switch (retval)
{ case dyrOK:
case dyrPATCHED:
{ break ; }
default:
{ errmsg(309,rtnnme,dy_sys->nme) ;
return (retval) ; } } }
/*
Attach and clear the vectors which will hold the status, values of primal and
dual variables, and reduced costs.
*/
if (consys_attach(dy_sys,CONSYS_ROW,
sizeof(flags),(void **) &dy_status) == FALSE)
{ errmsg(100,rtnnme,dy_sys->nme,"status vector") ;
return (dyrFATAL) ; }
if (consys_attach(dy_sys,CONSYS_COL,
sizeof(double),(void **) &dy_xbasic) == FALSE)
{ errmsg(100,rtnnme,dy_sys->nme,"basic variable vector") ;
return (dyrFATAL) ; }
if (consys_attach(dy_sys,CONSYS_ROW,
sizeof(double),(void **) &dy_x) == FALSE)
{ errmsg(100,rtnnme,dy_sys->nme,"primal variable vector") ;
return (dyrFATAL) ; }
if (consys_attach(dy_sys,CONSYS_COL,
sizeof(double),(void **) &dy_y) == FALSE)
{ errmsg(100,rtnnme,dy_sys->nme,"dual variable vector") ;
return (dyrFATAL) ; }
if (consys_attach(dy_sys,CONSYS_ROW,
sizeof(double),(void **) &dy_cbar) == FALSE)
{ errmsg(100,rtnnme,dy_sys->nme,"reduced cost vector") ;
return (dyrFATAL) ; }
/*
Calculate dual variables and reduced costs. Might as well make a try for a
dual feasible start, eh?
*/
# ifndef DYLP_NDEBUG
if (dy_opts->print.crash >= 2)
dyio_outfmt(dy_logchn,dy_gtxecho,"\n calculating dual values ...") ;
# endif
dy_calcduals() ;
if (dy_calccbar() == FALSE)
{ errmsg(384,rtnnme,dy_sys->nme,
dy_prtlpphase(dy_lp->phase,TRUE),dy_lp->tot.iters) ;
return (dyrFATAL) ; }
/*
Initialise dy_status for logicals, using dy_var2basis and dy_cbar as guides.
We have to consider the type of constraint so that we can give artificials
NBFX status (thus avoiding the issue of whether NBLB or NBUB gives dual
feasibility), and so that we can check the sign of the associated reduced
cost to determine the proper bound for the logical associated with a range
constraint.
*/
vlb = dy_sys->vlb ;
vub = dy_sys->vub ;
# ifndef DYLP_NDEBUG
if (dy_opts->print.crash >= 2)
{ dyio_outfmt(dy_logchn,dy_gtxecho,
"\n establishing initial status and reference frame ...") ;
dyio_outfmt(dy_logchn,dy_gtxecho,"\n logicals ...") ; }
# endif
for (dyvndx = 1 ; dyvndx <= dy_sys->concnt ; dyvndx++)
{ if (dy_var2basis[dyvndx] != 0)
{ if (vub[dyvndx] == vlb[dyvndx])
dy_status[dyvndx] = vstatBFX ;
else
dy_status[dyvndx] = vstatB ; }
else
{ switch (dy_sys->ctyp[dyvndx])
{ case contypLE:
case contypGE:
{ dy_status[dyvndx] = vstatNBLB ;
dy_x[dyvndx] = 0 ;
break ; }
case contypEQ:
{ dy_status[dyvndx] = vstatNBFX ;
dy_x[dyvndx] = 0 ;
break ; }
case contypRNG:
{ if (vub[dyvndx] == vlb[dyvndx])
{ dy_status[dyvndx] = vstatNBFX ;
dy_x[dyvndx] = vub[dyvndx] ; }
else
if (dy_cbar[dyvndx] < 0)
{ dy_status[dyvndx] = vstatNBUB ;
dy_x[dyvndx] = vub[dyvndx] ; }
else
{ dy_status[dyvndx] = vstatNBLB ;
dy_x[dyvndx] = vlb[dyvndx] ; }
break ; }
default:
{ errmsg(1,rtnnme,__LINE__) ;
return (dyrFATAL) ; } } }
# ifndef DYLP_NDEBUG
if (dy_opts->print.crash >= 4)
{ dyio_outfmt(dy_logchn,dy_gtxecho,"\n\t %s (%d) %s",
consys_nme(dy_sys,'v',dyvndx,FALSE,NULL),dyvndx,
dy_prtvstat(dy_status[dyvndx])) ;
if (flgon(dy_status[dyvndx],vstatNONBASIC|vstatNBFR))
dyio_outfmt(dy_logchn,dy_gtxecho," with value %g.",dy_x[dyvndx]) ;
else
dyio_outchr(dy_logchn,dy_gtxecho,'.') ; }
# endif
}
/*
Scan dy_origvars, with two purposes in mind:
* For active architectural variables, initialise dy_status from
orig_status, using the actual status for nonbasic variables, and
vstatB, vstatBFX, or vstatBFR for basic variables. (We'll tune this
once we have the values of the basic variables.) Initialise dy_x to the
proper value for nonbasic variables. We shouldn't see NBFX here, as
those variables should have been left inactive.
* For inactive architectural variables, accumulate the objective function
correction. Nonbasic free variables are assumed to have value 0.
*/
# ifndef DYLP_NDEBUG
if (dy_opts->print.crash >= 2)
dyio_outfmt(dy_logchn,dy_gtxecho,"\n architecturals ...") ;
# endif
dy_lp->inactzcorr = 0 ;
for (vndx = 1 ; vndx <= orig_sys->varcnt ; vndx++)
{ dyvndx = dy_origvars[vndx] ;
if (dyvndx < 0)
{ obj = orig_sys->obj[vndx] ;
switch ((flags) (-dyvndx))
{ case vstatNBFX:
case vstatNBLB:
{ dy_lp->inactzcorr += obj*orig_sys->vlb[vndx] ;
break ; }
case vstatNBUB:
{ dy_lp->inactzcorr += obj*orig_sys->vub[vndx] ;
break ; }
# ifdef DYLP_PARANOIA
case vstatNBFR:
{ break ; }
default:
{ errmsg(1,rtnnme,__LINE__) ;
return (dyrINV) ; }
# endif
} }
else
{ if (((int) orig_status[vndx]) < 0)
{ if (vlb[dyvndx] == vub[dyvndx])
dy_status[dyvndx] = vstatBFX ;
else
if (vlb[dyvndx] <= -dy_tols->inf && vub[dyvndx] >= dy_tols->inf)
dy_status[dyvndx] = vstatBFR ;
else
dy_status[dyvndx] = vstatB ; }
else
{ dy_status[dyvndx] = orig_status[vndx] ;
switch (dy_status[dyvndx])
{ case vstatNBLB:
{ dy_x[dyvndx] = vlb[dyvndx] ;
break ; }
case vstatNBUB:
{ dy_x[dyvndx] = vub[dyvndx] ;
break ; }
case vstatNBFR:
{ dy_x[dyvndx] = 0 ;
break ; }
# ifdef DYLP_PARANOIA
default:
{ errmsg(1,rtnnme,__LINE__) ;
return (dyrINV) ; }
# endif
} }
# ifndef DYLP_NDEBUG
if (dy_opts->print.crash >= 4)
{ dyio_outfmt(dy_logchn,dy_gtxecho,"\n\t %s (%d) %s",
consys_nme(dy_sys,'v',dyvndx,FALSE,NULL),dyvndx,
dy_prtvstat(dy_status[dyvndx])) ;
if (flgon(dy_status[dyvndx],vstatNONBASIC|vstatNBFR))
dyio_outfmt(dy_logchn,dy_gtxecho," with value %g.",dy_x[dyvndx]) ;
else
dyio_outchr(dy_logchn,dy_gtxecho,'.') ; }
# endif
} }
/*
Did we patch the basis? If so, we need to scan the status array and correct
the entries for the architectural variables that were booted out during the
patch.
*/
if (retval == dyrPATCHED) correct_for_patch() ;
/*
Ok, status is set. Now it's time to calculate initial values for the primal
variables and objective. Arguably we don't need the true objective for
phase I, but it's cheap to calculate. Once we have the primal variables,
adjust the status for any that are pinned against a bound or out of bounds,
and see how it looks, in terms of primal infeasibility.
*/
# ifndef DYLP_NDEBUG
if (dy_opts->print.crash >= 2)
dyio_outfmt(dy_logchn,dy_gtxecho,"\n calculating primal values ...") ;
# endif
if (dy_calcprimals() == FALSE)
{ errmsg(316,rtnnme,dy_sys->nme) ;
return (dyrFATAL) ; }
dy_lp->z = dy_calcobj() ;
dy_setfinalstatus() ;
/*
Make the check for primal and/or dual feasibility, and set the initial
simplex phase accordingly.
*/
calcflgs = ladPRIMFEAS|ladPFQUIET|ladDUALFEAS|ladDFQUIET ;
retval = dy_accchk(&calcflgs) ;
if (retval != dyrOK)
{ errmsg(304,rtnnme,dy_sys->nme,
dy_prtlpphase(dy_lp->phase,TRUE),dy_lp->tot.iters) ;
return (retval) ; }
if (flgoff(calcflgs,ladPRIMFEAS))
{ dy_lp->simplex.next = dyPRIMAL2 ; }
else
if (flgoff(calcflgs,ladDUALFEAS))
{ dy_lp->simplex.next = dyDUAL ; }
else
{ dy_lp->simplex.next = dyPRIMAL1 ; }
# ifndef DYLP_NDEBUG
if (dy_opts->print.crash >= 2)
{ dyio_outfmt(dy_logchn,dy_gtxecho,"\n phase %s, initial objective %g",
dy_prtlpphase(dy_lp->simplex.next,FALSE),dy_lp->z) ;
if (dy_lp->infeascnt != 0)
dyio_outfmt(dy_logchn,dy_gtxecho,", %d infeasible vars, infeas = %g",
dy_lp->infeascnt,dy_lp->infeas) ;
dyio_outchr(dy_logchn,dy_gtxecho,'.') ; }
if (dy_opts->print.crash >= 3)
{ dyio_outfmt(dy_logchn,dy_gtxecho,
"\n\nPos'n\tConstraint\tDual\t\tPrimal\n") ;
for (bpos = 1 ; bpos <= dy_sys->concnt; bpos++)
{ cndx = dy_actcons[bpos] ;
dyvndx = dy_basis[bpos] ;
if (dyvndx <= dy_sys->concnt)
vndx = orig_sys->varcnt+dyvndx ;
else
vndx = dy_actvars[dyvndx] ;
dyio_outfmt(dy_logchn,dy_gtxecho,
"\n%5d\t(%4d) %-8s\t%12.4g\t(%4d) %-8s %12.4g",
bpos,cndx,
consys_nme(dy_sys,'c',bpos,FALSE,NULL),dy_y[bpos],vndx,
consys_nme(dy_sys,'v',dyvndx,FALSE,NULL),dy_x[dyvndx]) ; } }
# endif
return (dyrOK) ; }
static bool process_inactive (lpprob_struct *orig_lp, int oxkndx)
/*
This routine handles the data structure updates for an inactive variable
x<k>. We need to have a look at the bounds l<k> and u<k>, and perhaps
update the status kept in dy_origvars. We need to add the contribution
c<k>l<k> or c<k>u<k> to the objective function. Finally, if we've reloaded
b & blow due to a bound or rhs change, we need to walk the column a<k>
and adjust b<i> (and perhaps blow<i>) for each nonzero a<ik> in the active
system.
Parameters:
orig_lp: the original lp problem
oxkndx: index of x<k> in orig_sys
Returns: TRUE if the update is made without incident, FALSE otherwise.
*/
{ int oaindx,aindx,ndx ;
double xk,lk,uk,ck ;
pkvec_struct *ak ;
pkcoeff_struct *aik ;
consys_struct *orig_sys ;
flags xkstatus ;
const char *rtnnme = "process_inactive" ;
orig_sys = orig_lp->consys ;
xkstatus = getflg(orig_lp->status[oxkndx],vstatSTATUS) ;
# ifdef DYLP_PARANOIA
/*
Any inactive variable should be nonbasic, and the paranoid check is looking
to make sure of this.
*/
if (!VALID_STATUS(xkstatus))
{ errmsg(300,rtnnme,(int) xkstatus,
consys_nme(orig_sys,'v',oxkndx,FALSE,NULL),oxkndx) ;
return (FALSE) ; }
if (flgoff(xkstatus,vstatNONBASIC|vstatNBFR))
{ errmsg(433,rtnnme,
dy_sys->nme,dy_prtlpphase(dy_lp->phase,TRUE),dy_lp->tot.iters,
"inactive",consys_nme(orig_sys,'v',oxkndx,TRUE,NULL),oxkndx,
dy_prtvstat(xkstatus)) ;
return (FALSE) ; }
# endif
/*
The bounds can change arbitrarily, and the client may not be maintaining
the status vector, but we're limited in what we can do --- bounds and status
are our only clues to the value of an inactive variable. (Contrast with the
equivalent section in process_active.)
*/
lk = orig_sys->vlb[oxkndx] ;
uk = orig_sys->vub[oxkndx] ;
ck = orig_sys->obj[oxkndx] ;
/*
Start with the case that both bounds are finite. Use a previous status of
NBLB or NBUB. Otherwise, guess from the sign of the objective coefficient.
`Dirty' fixed variables are marked as unloadable.
*/
if (lk > -dy_tols->inf && uk < dy_tols->inf)
{ if (atbnd(lk,uk) && lk != uk)
{ if (flgon(xkstatus,vstatNBLB|vstatNBUB))
{ setflg(xkstatus,vstatNOLOAD) ; }
else
{ if (ck < 0)
{ xkstatus = vstatNBUB|vstatNOLOAD ; }
else
{ xkstatus = vstatNBLB|vstatNOLOAD ; } }
# ifndef DYLP_NDEBUG
if (dy_opts->print.setup >= 3)
{ dyio_outfmt(dy_logchn,dy_gtxecho,"\n\tDirty fixed variable %s (%d)",
consys_nme(orig_sys,'v',oxkndx,0,0),oxkndx) ;
dyio_outfmt(dy_logchn,dy_gtxecho,
" assigned status %s.",dy_prtvstat(xkstatus)) ;
dyio_outfmt(dy_logchn,dy_gtxecho,
"\n\t original lb = %g, ub = %g, diff = %g, tol = %g",
lk,uk,uk-lk,dy_tols->pfeas) ; }
# endif
}
else
if (lk == uk)
{ xkstatus = vstatNBFX|vstatNOLOAD ; }
else
if (flgon(xkstatus,vstatNBLB|vstatNBUB))
{ xkstatus = orig_lp->status[oxkndx] ; }
else
{ if (ck < 0)
{ xkstatus = vstatNBUB ; }
else
{ xkstatus = vstatNBLB ; } } }
/*
Variables with one bound, or no bounds. No choices here.
*/
else
if (lk > -dy_tols->inf)
{ xkstatus = vstatNBLB ; }
else
if (uk < dy_tols->inf)
{ xkstatus = vstatNBUB ; }
else
{ xkstatus = vstatNBFR ; }
/*
Determine the variable's value and set up the status entries.
The default case in the switch below should never execute, but it serves
for paranoia and lets gcc conclude xk will always have a value.
Consider whether it's really a good idea to change orig_lp->status.
*/
switch (getflg(xkstatus,vstatSTATUS))
{ case vstatNBLB:
case vstatNBFX:
{ xk = lk ;
break ; }
case vstatNBUB:
{ xk = uk ;
break ; }
case vstatNBFR:
{ xk = 0 ;
break ; }
default:
{ xk = 0 ;
errmsg(1,rtnnme,__LINE__) ;
return (FALSE) ; } }
orig_lp->status[oxkndx] = xkstatus ;
dy_origvars[oxkndx] = -((int) xkstatus) ;
/*
Note any contribution to the objective and constraint rhs & rhslow values.
*/
dy_lp->inactzcorr += xk*orig_sys->obj[oxkndx] ;
if (flgon(orig_lp->ctlopts,lpctlRHSCHG|lpctlLBNDCHG|lpctlUBNDCHG))
{ ak = NULL ;
if (consys_getcol_pk(orig_sys,oxkndx,&ak) == FALSE)
{ errmsg(122,rtnnme,orig_sys->nme,"variable",
consys_nme(orig_sys,'v',oxkndx,TRUE,NULL),oxkndx) ;
if (ak != NULL) pkvec_free(ak) ;
return (FALSE) ; }
for (ndx = 0, aik = &ak->coeffs[0] ; ndx < ak->cnt ; ndx++, aik++)
{ oaindx = aik->ndx ;
if (ACTIVE_CON(oaindx))
{ aindx = dy_origcons[oaindx] ;
dy_sys->rhs[aindx] -= aik->val*xk ;
if (dy_sys->ctyp[aindx] == contypRNG)
dy_sys->rhslow[aindx] -= aik->val*xk ; } }
pkvec_free(ak) ; }
/*
And we're done. Print some information and return.
*/
# ifndef DYLP_NDEBUG
if (dy_opts->print.crash >= 4)
{ dyio_outfmt(dy_logchn,dy_gtxecho,"\n\t %s (%d) %s inactive with value ",
consys_nme(orig_sys,'v',oxkndx,FALSE,NULL),oxkndx,
dy_prtvstat(xkstatus)) ;
switch (getflg(xkstatus,vstatSTATUS))
{ case vstatNBFX:
case vstatNBLB:
case vstatNBUB:
case vstatNBFR:
{ dyio_outfmt(dy_logchn,dy_gtxecho,"%g.",xk) ;
break ; }
default:
{ dyio_outfmt(dy_logchn,dy_gtxecho,"??.") ;
break ; } } }
# endif
return (TRUE) ; }
static int factor_loadcol (void *p_consys, int i, int *rndx, double *coeff)
/*
This routine is used by luf_decomp to load columns of the basis into its
internal data structure. The requirements are that it load rndx[] and
coeff[] with the row indices and coefficients, respectively, of column i
of the basis, returning the number of coefficients.
Here, we need to look up the index j of the variable that actually occupies
basis position i, retrieve the column, and load it into rndx and coeff.
Parameters:
p_consys: a consys_struct
i: basis index
rndx: (o) row indices i of coefficients a<ij>
coeff: (o) coefficients a<ij>
Returns: number of coefficients, or -1 in the event of an error.
*/
{ int j,vecndx,pkndx ;
double aij ;
pkvec_struct *aj ;
consys_struct *consys ;
const char *rtnnme = "factor_loadcol" ;
# ifdef DYLP_PARANOIA
if (p_consys == NULL)
{ errmsg(2,rtnnme,"consys") ;
return (-1) ; }
if (rndx == NULL)
{ errmsg(2,rtnnme,"row index vector") ;
return (-1) ; }
if (coeff == NULL)
{ errmsg(2,rtnnme,"coefficient") ;
return (-1) ; }
# endif
consys = (consys_struct *) p_consys ;
aj = pkvec_new(consys->maxcollen) ;
/*
Retrieve the column ...
*/
j = dy_basis[i] ;
if (consys_getcol_pk(consys,j,&aj) == FALSE)
{ errmsg(112,rtnnme,dy_sys->nme,"retrieve","column",
consys_nme(dy_sys,'v',j,FALSE,NULL),j) ;
if (aj != NULL) pkvec_free(aj) ;
return (-1) ; }
/*
... and load it into the return vectors rndx and coeff.
*/
vecndx = 1 ;
for (pkndx = 0 ; pkndx < aj->cnt ; pkndx++)
{ aij = aj->coeffs[pkndx].val ;
if (aij != 0.0)
{ rndx[vecndx] = aj->coeffs[pkndx].ndx ;
coeff[vecndx] = aij ;
vecndx++ ; } }
/*
Clean up and return.
*/
pkvec_free(aj) ;
return (vecndx-1) ; }