/** creates a relaxation handler */
SCIP_RETCODE SCIPrelaxCreate(
SCIP_RELAX** relax, /**< pointer to relaxation handler data structure */
SCIP_SET* set, /**< global SCIP settings */
SCIP_MESSAGEHDLR* messagehdlr, /**< message handler */
BMS_BLKMEM* blkmem, /**< block memory for parameter settings */
const char* name, /**< name of relaxation handler */
const char* desc, /**< description of relaxation handler */
int priority, /**< priority of the relaxation handler (negative: after LP, non-negative: before LP) */
int freq, /**< frequency for calling relaxation handler */
SCIP_DECL_RELAXCOPY ((*relaxcopy)), /**< copy method of relaxation handler or NULL if you don't want to copy your plugin into sub-SCIPs */
SCIP_DECL_RELAXFREE ((*relaxfree)), /**< destructor of relaxation handler */
SCIP_DECL_RELAXINIT ((*relaxinit)), /**< initialize relaxation handler */
SCIP_DECL_RELAXEXIT ((*relaxexit)), /**< deinitialize relaxation handler */
SCIP_DECL_RELAXINITSOL((*relaxinitsol)), /**< solving process initialization method of relaxation handler */
SCIP_DECL_RELAXEXITSOL((*relaxexitsol)), /**< solving process deinitialization method of relaxation handler */
SCIP_DECL_RELAXEXEC ((*relaxexec)), /**< execution method of relaxation handler */
SCIP_RELAXDATA* relaxdata /**< relaxation handler data */
)
{
char paramname[SCIP_MAXSTRLEN];
char paramdesc[SCIP_MAXSTRLEN];
assert(relax != NULL);
assert(name != NULL);
assert(desc != NULL);
assert(freq >= -1);
assert(relaxexec != NULL);
SCIP_ALLOC( BMSallocMemory(relax) );
SCIP_ALLOC( BMSduplicateMemoryArray(&(*relax)->name, name, strlen(name)+1) );
SCIP_ALLOC( BMSduplicateMemoryArray(&(*relax)->desc, desc, strlen(desc)+1) );
(*relax)->priority = priority;
(*relax)->freq = freq;
(*relax)->relaxcopy = relaxcopy;
(*relax)->relaxfree = relaxfree;
(*relax)->relaxinit = relaxinit;
(*relax)->relaxexit = relaxexit;
(*relax)->relaxinitsol = relaxinitsol;
(*relax)->relaxexitsol = relaxexitsol;
(*relax)->relaxexec = relaxexec;
(*relax)->relaxdata = relaxdata;
SCIP_CALL( SCIPclockCreate(&(*relax)->setuptime, SCIP_CLOCKTYPE_DEFAULT) );
SCIP_CALL( SCIPclockCreate(&(*relax)->relaxclock, SCIP_CLOCKTYPE_DEFAULT) );
(*relax)->ncalls = 0;
(*relax)->lastsolvednode = -1;
(*relax)->initialized = FALSE;
/* add parameters */
(void) SCIPsnprintf(paramname, SCIP_MAXSTRLEN, "relaxing/%s/priority", name);
(void) SCIPsnprintf(paramdesc, SCIP_MAXSTRLEN, "priority of relaxation handler <%s>", name);
SCIP_CALL( SCIPsetAddIntParam(set, messagehdlr, blkmem, paramname, paramdesc,
&(*relax)->priority, FALSE, priority, INT_MIN/4, INT_MAX/4,
paramChgdRelaxPriority, (SCIP_PARAMDATA*)(*relax)) ); /*lint !e740*/
(void) SCIPsnprintf(paramname, SCIP_MAXSTRLEN, "relaxing/%s/freq", name);
(void) SCIPsnprintf(paramdesc, SCIP_MAXSTRLEN, "frequency for calling relaxation handler <%s> (-1: never, 0: only in root node)", name);
SCIP_CALL( SCIPsetAddIntParam(set, messagehdlr, blkmem, paramname, paramdesc,
&(*relax)->freq, FALSE, freq, -1, INT_MAX, NULL, NULL) );
return SCIP_OKAY;
}
/** creates a variable pricer
* To use the variable pricer for solving a problem, it first has to be activated with a call to SCIPactivatePricer().
*/
SCIP_RETCODE SCIPpricerCreate(
SCIP_PRICER** pricer, /**< pointer to variable pricer data structure */
SCIP_SET* set, /**< global SCIP settings */
BMS_BLKMEM* blkmem, /**< block memory for parameter settings */
const char* name, /**< name of variable pricer */
const char* desc, /**< description of variable pricer */
int priority, /**< priority of the variable pricer */
SCIP_Bool delay, /**< should the pricer be delayed until no other pricers or already existing
* problem variables with negative reduced costs are found */
SCIP_DECL_PRICERCOPY ((*pricercopy)), /**< copy method of pricer or NULL if you don't want to copy your plugin into sub-SCIPs */
SCIP_DECL_PRICERFREE ((*pricerfree)), /**< destructor of variable pricer */
SCIP_DECL_PRICERINIT ((*pricerinit)), /**< initialize variable pricer */
SCIP_DECL_PRICEREXIT ((*pricerexit)), /**< deinitialize variable pricer */
SCIP_DECL_PRICERINITSOL((*pricerinitsol)),/**< solving process initialization method of variable pricer */
SCIP_DECL_PRICEREXITSOL((*pricerexitsol)),/**< solving process deinitialization method of variable pricer */
SCIP_DECL_PRICERREDCOST((*pricerredcost)),/**< reduced cost pricing method of variable pricer for feasible LPs */
SCIP_DECL_PRICERFARKAS((*pricerfarkas)), /**< Farkas pricing method of variable pricer for infeasible LPs */
SCIP_PRICERDATA* pricerdata /**< variable pricer data */
)
{
char paramname[SCIP_MAXSTRLEN];
char paramdesc[SCIP_MAXSTRLEN];
assert(pricer != NULL);
assert(name != NULL);
assert(desc != NULL);
assert(pricerredcost != NULL);
SCIP_ALLOC( BMSallocMemory(pricer) );
SCIP_ALLOC( BMSduplicateMemoryArray(&(*pricer)->name, name, strlen(name)+1) );
SCIP_ALLOC( BMSduplicateMemoryArray(&(*pricer)->desc, desc, strlen(desc)+1) );
(*pricer)->priority = priority;
(*pricer)->pricercopy = pricercopy;
(*pricer)->pricerfree = pricerfree;
(*pricer)->pricerinit = pricerinit;
(*pricer)->pricerexit = pricerexit;
(*pricer)->pricerinitsol = pricerinitsol;
(*pricer)->pricerexitsol = pricerexitsol;
(*pricer)->pricerredcost = pricerredcost;
(*pricer)->pricerfarkas = pricerfarkas;
(*pricer)->pricerdata = pricerdata;
SCIP_CALL( SCIPclockCreate(&(*pricer)->pricerclock, SCIP_CLOCKTYPE_DEFAULT) );
(*pricer)->ncalls = 0;
(*pricer)->nvarsfound = 0;
(*pricer)->delay = delay;
(*pricer)->active = FALSE;
(*pricer)->initialized = FALSE;
/* add parameters */
(void) SCIPsnprintf(paramname, SCIP_MAXSTRLEN, "pricers/%s/priority", name);
(void) SCIPsnprintf(paramdesc, SCIP_MAXSTRLEN, "priority of pricer <%s>", name);
SCIP_CALL( SCIPsetAddIntParam(set, blkmem, paramname, paramdesc,
&(*pricer)->priority, FALSE, priority, INT_MIN/4, INT_MAX/4,
paramChgdPricerPriority, (SCIP_PARAMDATA*)(*pricer)) ); /*lint !e740*/
return SCIP_OKAY;
}
/** issues an error message and marks the LP data to have errors */
static
void syntaxError(
SCIP* scip, /**< SCIP data structure */
LPINPUT* lpinput, /**< LP reading data */
const char* msg /**< error message */
)
{
char formatstr[256];
assert(lpinput != NULL);
SCIPerrorMessage("Syntax error in line %d ('%s'): %s \n", lpinput->linenumber, lpinput->token, msg);
if( lpinput->linebuf[strlen(lpinput->linebuf)-1] == '\n' )
{
SCIPverbMessage(scip, SCIP_VERBLEVEL_MINIMAL, NULL, " input: %s", lpinput->linebuf);
}
else
{
SCIPverbMessage(scip, SCIP_VERBLEVEL_MINIMAL, NULL, " input: %s\n", lpinput->linebuf);
}
(void) SCIPsnprintf(formatstr, 256, " %%%ds\n", lpinput->linepos);
SCIPverbMessage(scip, SCIP_VERBLEVEL_MINIMAL, NULL, (const char*)formatstr, "^");
lpinput->section = LP_END;
lpinput->haserror = TRUE;
}
/** issues an error message and marks the BLK data to have errors */
static
void syntaxError(
SCIP* scip, /**< SCIP data structure */
BLKINPUT* blkinput, /**< BLK reading data */
const char* msg /**< error message */
)
{
char formatstr[256];
assert(blkinput != NULL);
SCIPverbMessage(scip, SCIP_VERBLEVEL_MINIMAL, NULL, "Syntax error in line %d: %s ('%s')\n",
blkinput->linenumber, msg, blkinput->token);
if( blkinput->linebuf[strlen(blkinput->linebuf)-1] == '\n' )
{
SCIPverbMessage(scip, SCIP_VERBLEVEL_MINIMAL, NULL, " input: %s", blkinput->linebuf);
}
else
{
SCIPverbMessage(scip, SCIP_VERBLEVEL_MINIMAL, NULL, " input: %s\n", blkinput->linebuf);
}
(void) SCIPsnprintf(formatstr, 256, " %%%ds\n", blkinput->linepos);
SCIPverbMessage(scip, SCIP_VERBLEVEL_MINIMAL, NULL, formatstr, "^");
blkinput->section = BLK_END;
blkinput->haserror = TRUE;
}
/** displays a time value fitting in a given width */
void SCIPdispTime(
SCIP_MESSAGEHDLR* messagehdlr, /**< message handler */
FILE* file, /**< output stream */
SCIP_Real val, /**< value in seconds to display */
int width /**< width to fit into */
)
{
assert(width >= 1);
if( width == 1 )
{
if( val < 0.0 )
SCIPmessageFPrintInfo(messagehdlr, file, "-");
else if( val < 10.0 )
SCIPmessageFPrintInfo(messagehdlr, file, "%.0f", val);
else
SCIPmessageFPrintInfo(messagehdlr, file, "+");
}
else
{
char format[SCIP_MAXSTRLEN];
SCIP_Longint maxval;
int timepower;
int i;
maxval = 1;
for( i = 0; i < width-1; ++i )
maxval *= 10;
if( val < 0.0 )
maxval /= 10;
timepower = 0;
while( REALABS(val) + 0.5 >= maxval && timepower < MAXTIMEPOWER )
{
timepower++;
val /= timepowerval[timepower];
}
if( REALABS(val) + 0.05 < maxval/100 ) /*lint !e653*/
(void) SCIPsnprintf(format, SCIP_MAXSTRLEN, "%%%d.1f%c", width-1, timepowerchar[timepower]);
else
(void) SCIPsnprintf(format, SCIP_MAXSTRLEN, "%%%d.0f%c", width-1, timepowerchar[timepower]);
if( width == 2 && val < 0.0 )
SCIPmessageFPrintInfo(messagehdlr, file, "-%c", timepowerchar[timepower]);
else
SCIPmessageFPrintInfo(messagehdlr, file, (const char*)format, val);
}
}
/** parese job informations */
static
SCIP_RETCODE getJobs(
SCIP* scip, /**< SCIP data structure */
int lineno, /**< current line number of input file */
char* linestr, /**< current line */
STATE* state, /**< pointer to current reading state */
SCIP_RCPSPDATA* rcpspdata /**< pointer to resources constrained project scheduling data */
)
{
char jobname[SCIP_MAXSTRLEN];
int value;
int jobid;
int r;
assert(linestr != NULL);
assert(state != NULL);
/* skip lines which are not of interest */
if ( (!strncmp(linestr, "REQUESTS", 4) ) || ( !strncmp(linestr, "jobnr", 3) ) || ( !strncmp(linestr, "-", 1) ) )
{
*state = JOBS;
return SCIP_OKAY;
}
/* parse job id */
SCIPstrToIntValue(linestr, &value, &linestr);
jobid = value - 1;
/* construct job name */
(void)SCIPsnprintf(jobname, SCIP_MAXSTRLEN, "%d" , jobid) ;
/* copy job name */
SCIP_CALL( SCIPduplicateBufferArray(scip, &rcpspdata->jobnames[jobid], jobname, strlen(jobname) + 1) );
/* skip next value */
SCIPstrToIntValue(linestr, &value, &linestr);
/* parse duration */
SCIPstrToIntValue(linestr, &value, &linestr);
rcpspdata->durations[jobid] = value;
SCIP_CALL( SCIPallocBufferArray(scip, &rcpspdata->demands[jobid], rcpspdata->nresources) );
/* parse demands */
for( r = 0; r < rcpspdata->nresources; ++r )
{
SCIPstrToIntValue(linestr, &value, &linestr);
rcpspdata->demands[jobid][r] = value;
}
/* check if we paresed the last job */
if(jobid == rcpspdata->njobs - 1)
*state = NEXT;
return SCIP_OKAY;
}
/** write a DEC file for a given decomposition */
SCIP_RETCODE GCGwriteDecomp(
SCIP* scip, /**< SCIP data structure */
FILE* file, /**< File pointer to write to */
DEC_DECOMP* decdecomp /**< Decomposition pointer */
)
{
char outname[SCIP_MAXSTRLEN];
assert(scip != NULL);
if( decdecomp == NULL )
{
SCIPwarningMessage(scip, "Cannot write decomposed problem if decomposition structure is empty!\n");
(void) SCIPsnprintf(outname, SCIP_MAXSTRLEN, "%s", SCIPgetProbName(scip));
}
else
{
(void) SCIPsnprintf(outname, SCIP_MAXSTRLEN, "%s_%d", SCIPgetProbName(scip), DECdecompGetNBlocks(decdecomp));
SCIP_CALL( writeData(scip, file, decdecomp) );
}
return SCIP_OKAY;
}
/** reads the next non-empty non-comment line of a cnf file */
static
SCIP_RETCODE readCnfLine(
SCIP* scip, /**< SCIP data structure */
SCIP_FILE* file, /**< input file */
char* buffer, /**< buffer for storing the input line */
int size, /**< size of the buffer */
int* linecount /**< pointer to the line number counter */
)
{
char* line;
int linelen;
assert(file != NULL);
assert(buffer != NULL);
assert(size >= 2);
assert(linecount != NULL);
do
{
(*linecount)++;
line = SCIPfgets(buffer, size, file);
if( line != NULL )
{
linelen = (int)strlen(line);
if( linelen == size-1 )
{
char s[SCIP_MAXSTRLEN];
(void) SCIPsnprintf(s, SCIP_MAXSTRLEN, "line too long (exceeds %d characters)", size-2);
readError(scip, *linecount, s);
return SCIP_READERROR;
}
}
else
linelen = 0;
}
while( line != NULL && (*line == 'c' || *line == '\n') );
if( line != NULL && linelen >= 2 && line[linelen-2] == '\n' )
line[linelen-2] = '\0';
else if( linelen == 0 )
*buffer = '\0';
assert((line == NULL) == (*buffer == '\0'));
return SCIP_OKAY;
}
/** displays a long integer in decimal form fitting in a given width */
void SCIPdispLongint(
SCIP_MESSAGEHDLR* messagehdlr, /**< message handler */
FILE* file, /**< output stream */
SCIP_Longint val, /**< value to display */
int width /**< width to fit into */
)
{
assert(width >= 1);
if( width == 1 )
{
if( val < 0 )
SCIPmessageFPrintInfo(messagehdlr, file, "-");
else if( val < 10 )
SCIPmessageFPrintInfo(messagehdlr, file, "%"SCIP_LONGINT_FORMAT, val);
else
SCIPmessageFPrintInfo(messagehdlr, file, "+");
}
else
{
char format[SCIP_MAXSTRLEN];
SCIP_Longint maxval;
int decpower;
int i;
maxval = 1;
for( i = 0; i < width-1; ++i )
maxval *= 10;
if( val < 0 )
maxval /= 10;
decpower = 0;
while( ABS(val) >= maxval && decpower < MAXDECPOWER )
{
decpower++;
val /= 1000;
}
(void) SCIPsnprintf(format, SCIP_MAXSTRLEN, "%%%d"SCIP_LONGINT_FORMAT"%c", width-1, decpowerchar[decpower]);
if( width == 2 && val < 0 )
SCIPmessageFPrintInfo(messagehdlr, file, "-%c", decpowerchar[decpower]);
else
SCIPmessageFPrintInfo(messagehdlr, file, (const char*)format, val);
}
}
/** create linear ordering problem model */
SCIP_RETCODE LOPgenerateModel(
SCIP* scip /**< SCIP data structure */
)
{
SCIP_PROBDATA* probdata;
SCIP_CONS* cons;
int i, j;
/* get problem data */
probdata = SCIPgetProbData(scip);
assert( probdata != NULL );
/* generate variables */
SCIP_CALL( SCIPallocMemoryArray(scip, &probdata->vars, probdata->n) );
for (i = 0; i < probdata->n; ++i)
{
SCIP_CALL( SCIPallocMemoryArray(scip, &(probdata->vars[i]), probdata->n) ); /*lint !e866*/
for (j = 0; j < probdata->n; ++j)
{
if (j != i)
{
char s[SCIP_MAXSTRLEN];
(void) SCIPsnprintf(s, SCIP_MAXSTRLEN, "x#%d#%d", i, j);
SCIP_CALL( SCIPcreateVar(scip, &(probdata->vars[i][j]), s, 0.0, 1.0, probdata->W[i][j], SCIP_VARTYPE_BINARY,
TRUE, FALSE, NULL, NULL, NULL, NULL, NULL));
SCIP_CALL( SCIPaddVar(scip, probdata->vars[i][j]) );
}
else
probdata->vars[i][j] = NULL;
}
}
/* generate linear ordering constraint */
SCIP_CALL( SCIPcreateConsLinearOrdering(scip, &cons, "LOP", probdata->n, probdata->vars, TRUE, TRUE, TRUE, TRUE, TRUE, FALSE,
FALSE, FALSE, FALSE, FALSE));
SCIP_CALL( SCIPaddCons(scip, cons) );
SCIP_CALL( SCIPreleaseCons(scip, &cons) );
/* set maximization */
SCIP_CALL( SCIPsetObjsense(scip, SCIP_OBJSENSE_MAXIMIZE) );
return SCIP_OKAY;
}
/** creates a tree compression */
SCIP_RETCODE SCIPcomprCreate(
SCIP_COMPR** compr, /**< pointer to tree compression data structure */
SCIP_SET* set, /**< global SCIP settings */
SCIP_MESSAGEHDLR* messagehdlr, /**< message handler */
BMS_BLKMEM* blkmem, /**< block memory for parameter settings */
const char* name, /**< name of tree compression */
const char* desc, /**< description of tree compression */
int priority, /**< priority of the tree compression */
int minnnodes, /**< minimal number of nodes for calling compression */
SCIP_DECL_COMPRCOPY ((*comprcopy)), /**< copy method of tree compression or NULL if you don't want to copy your plugin into sub-SCIPs */
SCIP_DECL_COMPRFREE ((*comprfree)), /**< destructor of tree compression */
SCIP_DECL_COMPRINIT ((*comprinit)), /**< initialize tree compression */
SCIP_DECL_COMPREXIT ((*comprexit)), /**< deinitialize tree compression */
SCIP_DECL_COMPRINITSOL ((*comprinitsol)), /**< solving process initialization method of tree compression */
SCIP_DECL_COMPREXITSOL ((*comprexitsol)), /**< solving process deinitialization method of tree compression */
SCIP_DECL_COMPREXEC ((*comprexec)), /**< execution method of tree compression */
SCIP_COMPRDATA* comprdata /**< tree compression data */
)
{
char paramname[SCIP_MAXSTRLEN];
char paramdesc[SCIP_MAXSTRLEN];
assert(compr != NULL);
assert(name != NULL);
assert(desc != NULL);
assert(comprexec != NULL);
SCIP_ALLOC( BMSallocMemory(compr) );
SCIP_ALLOC( BMSduplicateMemoryArray(&(*compr)->name, name, strlen(name)+1) );
SCIP_ALLOC( BMSduplicateMemoryArray(&(*compr)->desc, desc, strlen(desc)+1) );
(*compr)->priority = priority;
(*compr)->minnnodes = minnnodes;
(*compr)->comprcopy = comprcopy;
(*compr)->comprfree = comprfree;
(*compr)->comprinit = comprinit;
(*compr)->comprexit = comprexit;
(*compr)->comprinitsol = comprinitsol;
(*compr)->comprexitsol = comprexitsol;
(*compr)->comprexec = comprexec;
(*compr)->comprdata = comprdata;
SCIP_CALL( SCIPclockCreate(&(*compr)->setuptime, SCIP_CLOCKTYPE_DEFAULT) );
SCIP_CALL( SCIPclockCreate(&(*compr)->comprclock, SCIP_CLOCKTYPE_DEFAULT) );
(*compr)->ncalls = 0;
(*compr)->nfound = 0;
(*compr)->rate = 0.0;
(*compr)->initialized = FALSE;
(*compr)->nnodes = 0;
(*compr)->loi = 0.0;
/* add parameters */
(void) SCIPsnprintf(paramname, SCIP_MAXSTRLEN, "compression/%s/priority", name);
(void) SCIPsnprintf(paramdesc, SCIP_MAXSTRLEN, "priority of compression <%s>", name);
SCIP_CALL( SCIPsetAddIntParam(set, messagehdlr, blkmem, paramname, paramdesc,
&(*compr)->priority, TRUE, priority, INT_MIN/4, INT_MAX/4,
paramChgdComprPriority, (SCIP_PARAMDATA*)(*compr)) ); /*lint !e740*/
(void) SCIPsnprintf(paramname, SCIP_MAXSTRLEN, "compression/%s/minnleaves", name);
(void) SCIPsnprintf(paramdesc, SCIP_MAXSTRLEN, "minimal number of leave nodes for calling tree compression <%s>", name);
SCIP_CALL( SCIPsetAddIntParam(set, messagehdlr, blkmem, paramname, paramdesc,
&(*compr)->minnnodes, FALSE, minnnodes, 1, INT_MAX, NULL, NULL) );
return SCIP_OKAY;
}
/** sets up the problem data */
SCIP_RETCODE SCIPprobdataCreate(
SCIP* scip, /**< SCIP data structure */
const char* probname, /**< problem name */
int* ids, /**< array of item ids */
SCIP_Longint* weights, /**< array containing the item weights */
int nitems, /**< number of items */
SCIP_Longint capacity /**< bin capacity */
)
{
SCIP_PROBDATA* probdata;
SCIP_CONS** conss;
char name[SCIP_MAXSTRLEN];
int i;
assert(scip != NULL);
/* create event handler if it does not exist yet */
if( SCIPfindEventhdlr(scip, EVENTHDLR_NAME) == NULL )
{
SCIP_CALL( SCIPincludeEventhdlrBasic(scip, NULL, EVENTHDLR_NAME, EVENTHDLR_DESC, eventExecAddedVar, NULL) );
}
/* create problem in SCIP and add non-NULL callbacks via setter functions */
SCIP_CALL( SCIPcreateProbBasic(scip, probname) );
SCIP_CALL( SCIPsetProbDelorig(scip, probdelorigBinpacking) );
SCIP_CALL( SCIPsetProbTrans(scip, probtransBinpacking) );
SCIP_CALL( SCIPsetProbDeltrans(scip, probdeltransBinpacking) );
SCIP_CALL( SCIPsetProbInitsol(scip, probinitsolBinpacking) );
SCIP_CALL( SCIPsetProbExitsol(scip, probexitsolBinpacking) );
/* set objective sense */
SCIP_CALL( SCIPsetObjsense(scip, SCIP_OBJSENSE_MINIMIZE) );
/* tell SCIP that the objective will be always integral */
SCIP_CALL( SCIPsetObjIntegral(scip) );
SCIP_CALL( SCIPallocBufferArray(scip, &conss, nitems) );
/* create set covering constraints for each item */
for( i = 0; i < nitems; ++i )
{
(void) SCIPsnprintf(name, SCIP_MAXSTRLEN, "item_%d", ids[i]);
SCIP_CALL( SCIPcreateConsBasicSetcover(scip, &conss[i], name, 0, NULL) );
/* declare constraint modifiable for adding variables during pricing */
SCIP_CALL( SCIPsetConsModifiable(scip, conss[i], TRUE) );
SCIP_CALL( SCIPaddCons(scip, conss[i]) );
}
/* create problem data */
SCIP_CALL( probdataCreate(scip, &probdata, NULL, conss, weights, ids, 0, nitems, capacity) );
SCIP_CALL( createInitialColumns(scip, probdata) );
/* set user problem data */
SCIP_CALL( SCIPsetProbData(scip, probdata) );
SCIP_CALL( SCIPpricerBinpackingActivate(scip, conss, weights, ids, nitems, capacity) );
/* free local buffer arrays */
SCIPfreeBufferArray(scip, &conss);
return SCIP_OKAY;
}
/** create initial columns */
static
SCIP_RETCODE createInitialColumns(
SCIP* scip, /**< SCIP data structure */
SCIP_PROBDATA* probdata /**< problem data */
)
{
SCIP_CONS** conss;
SCIP_VARDATA* vardata;
SCIP_VAR* var;
char name[SCIP_MAXSTRLEN];
int* ids;
SCIP_Longint* weights;
int nitems;
int i;
conss = probdata->conss;
ids = probdata->ids;
weights = probdata->weights;
nitems = probdata->nitems;
/* create start solution each item in exactly one bin */
for( i = 0; i < nitems; ++i )
{
(void) SCIPsnprintf(name, SCIP_MAXSTRLEN, "item_%d", ids[i]);
SCIPdebugMessage("create variable for item %d with weight = %"SCIP_LONGINT_FORMAT"\n", ids[i], weights[i]);
/* create variable for the packing pattern which contains only this item */
SCIP_CALL( SCIPcreateVarBinpacking(scip, &var, name, 1.0, TRUE, TRUE, NULL) );
/* add variable to the problem */
SCIP_CALL( SCIPaddVar(scip, var) );
/* store variable in the problme data */
SCIP_CALL( SCIPprobdataAddVar(scip, probdata, var) );
/* add variable to corresponding set covering constraint */
SCIP_CALL( SCIPaddCoefSetppc(scip, conss[i], var) );
/* create the variable data for the variable; the variable data contains the information in which constraints the
* variable appears */
SCIP_CALL( SCIPvardataCreateBinpacking(scip, &vardata, &i, 1) );
/* add the variable data to the variable */
SCIPvarSetData(var, vardata);
/* change the upper bound of the binary variable to lazy since the upper bound is already enforced
* due to the objective function the set covering constraint;
* The reason for doing is that, is to avoid the bound of x <= 1 in the LP relaxation since this bound
* constraint would produce a dual variable which might have a positive reduced cost
*/
SCIP_CALL( SCIPchgVarUbLazy(scip, var, 1.0) );
/* release variable */
SCIP_CALL( SCIPreleaseVar(scip, &var) );
}
return SCIP_OKAY;
}
/** method for either Farkas or Redcost pricing */
static
SCIP_RETCODE pricing(
SCIP* scip, /**< SCIP data structure */
SCIP_PRICER* pricer, /**< pricer */
SCIP_Real* lowerbound, /**< lowerbound pointer */
SCIP_Bool farkas /**< TRUE: Farkas pricing; FALSE: Redcost pricing */
)
{
SCIP_PRICERDATA* pricerdata; /* the data of the pricer */
SCIP_PROBDATA* probdata;
GRAPH* graph;
SCIP_VAR* var;
PATH* path;
SCIP_Real* edgecosts; /* edgecosts of the current subproblem */
char varname[SCIP_MAXSTRLEN];
SCIP_Real newlowerbound = -SCIPinfinity(scip);
SCIP_Real redcost; /* reduced cost */
int tail;
int e;
int t;
int i;
assert(scip != NULL);
assert(pricer != NULL);
/* get pricer data */
pricerdata = SCIPpricerGetData(pricer);
assert(pricerdata != NULL);
/* get problem data */
probdata = SCIPgetProbData(scip);
assert(probdata != NULL);
SCIPdebugMessage("solstat=%d\n", SCIPgetLPSolstat(scip));
if( !farkas && SCIPgetLPSolstat(scip) == SCIP_LPSOLSTAT_OPTIMAL )
newlowerbound = SCIPgetSolTransObj(scip, NULL);
SCIPdebug( SCIP_CALL( SCIPprintSol(scip, NULL, NULL, FALSE) ) );
# if 0
if ( pricerdata->lowerbound <= 4 )
{
char label[SCIP_MAXSTRLEN];
(void)SCIPsnprintf(label, SCIP_MAXSTRLEN, "X%g.gml", pricerdata->lowerbound);
SCIP_CALL( SCIPprobdataPrintGraph(scip, label , NULL, TRUE) );
pricerdata->lowerbound++;
}
#endif
/* get the graph*/
graph = SCIPprobdataGetGraph(probdata);
/* get dual solutions and save them in mi and pi */
for( t = 0; t < pricerdata->realnterms; ++t )
{
if( farkas )
{
pricerdata->mi[t] = SCIPgetDualfarkasLinear(scip, pricerdata->pathcons[t]);
}
else
{
pricerdata->mi[t] = SCIPgetDualsolLinear(scip, pricerdata->pathcons[t]);
assert(!SCIPisNegative(scip, pricerdata->mi[t]));
}
}
for( e = 0; e < pricerdata->nedges; ++e )
{
if( !pricerdata->bigt )
{
for( t = 0; t < pricerdata->realnterms; ++t )
{
if( farkas )
{
pricerdata->pi[t * pricerdata->nedges + e] = SCIPgetDualfarkasLinear(
scip, pricerdata->edgecons[t * pricerdata->nedges + e]);
}
else
{
pricerdata->pi[t * pricerdata->nedges + e] = SCIPgetDualsolLinear(
scip, pricerdata->edgecons[t * pricerdata->nedges + e]);
}
}
}
else
{
if( farkas )
{
pricerdata->pi[e] = SCIPgetDualfarkasLinear(
scip, pricerdata->edgecons[e]);
}
else
{
pricerdata->pi[e] = SCIPgetDualsolLinear(
scip, pricerdata->edgecons[e]);
}
}
}
SCIP_CALL( SCIPallocMemoryArray(scip, &path, graph->knots) );
SCIP_CALL( SCIPallocMemoryArray(scip, &edgecosts, pricerdata->nedges) );
if( pricerdata->bigt )
{
for( e = 0; e < pricerdata->nedges; ++e )
{
edgecosts[e] = (-pricerdata->pi[e]);
}
}
/* find shortest r-t (r root, t terminal) paths and create corresponding variables iff reduced cost < 0 */
for( t = 0; t < pricerdata->realnterms; ++t )
{
for( e = 0; e < pricerdata->nedges; ++e )
{
if( !pricerdata->bigt )
{
edgecosts[e] = (-pricerdata->pi[t * pricerdata->nedges + e]);
}
assert(!SCIPisNegative(scip, edgecosts[e]));
}
for( i = 0; i < graph->knots; i++ )
graph->mark[i] = 1;
graph_path_exec(scip, graph, FSP_MODE, pricerdata->root, edgecosts, path);
/* compute reduced cost of shortest path to terminal t */
redcost = 0.0;
tail = pricerdata->realterms[t];
while( tail != pricerdata->root )
{
redcost += edgecosts[path[tail].edge];
tail = graph->tail[path[tail].edge];
}
redcost -= pricerdata->mi[t];
if( !farkas && SCIPgetLPSolstat(scip) == SCIP_LPSOLSTAT_OPTIMAL )
{
newlowerbound += redcost;
}
/* check if reduced cost < 0 */
if( SCIPisNegative(scip, redcost) )
{
/* create variable to the shortest path (having reduced cost < 0) */
var = NULL;
sprintf(varname, "PathVar%d_%d", t, pricerdata->ncreatedvars[t]);
++(pricerdata->ncreatedvars[t]);
SCIP_CALL( SCIPcreateVarBasic(scip, &var, varname, 0.0, SCIPinfinity(scip), 0.0, SCIP_VARTYPE_CONTINUOUS) );
SCIP_CALL( SCIPaddPricedVar(scip, var, -redcost) );
tail = pricerdata->realterms[t];
while( tail != pricerdata->root )
{
/* add variable to constraints */
if( !pricerdata->bigt )
{
SCIP_CALL( SCIPaddCoefLinear(scip, pricerdata->edgecons[t * pricerdata->nedges + path[tail].edge], var, 1.0) );
}
else
{
SCIP_CALL( SCIPaddCoefLinear(scip, pricerdata->edgecons[path[tail].edge], var, 1.0) );
}
tail = graph->tail[path[tail].edge];
}
SCIP_CALL( SCIPaddCoefLinear(scip, pricerdata->pathcons[t], var, 1.0) );
}
}
if( !farkas && SCIPgetLPSolstat(scip) == SCIP_LPSOLSTAT_OPTIMAL )
*lowerbound = newlowerbound;
SCIPfreeMemoryArray(scip, &edgecosts);
SCIPfreeMemoryArray(scip, &path);
return SCIP_OKAY;
}
/** presolving execution method */
static
SCIP_DECL_PRESOLEXEC(presolExecBoundshift)
{ /*lint --e{715}*/
SCIP_PRESOLDATA* presoldata;
SCIP_VAR** scipvars;
SCIP_VAR** vars;
int nbinvars;
int nvars;
int v;
assert(scip != NULL);
assert(presol != NULL);
assert(strcmp(SCIPpresolGetName(presol), PRESOL_NAME) == 0);
assert(result != NULL);
*result = SCIP_DIDNOTRUN;
/* get presolver data */
presoldata = SCIPpresolGetData(presol);
assert(presoldata != NULL);
/* get the problem variables */
scipvars = SCIPgetVars(scip);
nbinvars = SCIPgetNBinVars(scip);
nvars = SCIPgetNVars(scip) - nbinvars;
if( nvars == 0 )
return SCIP_OKAY;
if( SCIPdoNotAggr(scip) )
return SCIP_OKAY;
*result = SCIP_DIDNOTFIND;
/* copy the integer variables into an own array, since adding new integer variables affects the left-most slots in
* the array and thereby interferes with our search loop
*/
SCIP_CALL( SCIPduplicateBufferArray(scip, &vars, &scipvars[nbinvars], nvars) );
/* scan the integer, implicit, and continuous variables for possible conversion */
for( v = nvars - 1; v >= 0; --v )
{
SCIP_VAR* var = vars[v];
SCIP_Real lb;
SCIP_Real ub;
assert(SCIPvarGetType(var) != SCIP_VARTYPE_BINARY);
/* get current variable's bounds */
lb = SCIPvarGetLbGlobal(var);
ub = SCIPvarGetUbGlobal(var);
assert( SCIPisLE(scip, lb, ub) );
if( SCIPisEQ(scip, lb, ub) )
continue;
if( presoldata->integer && !SCIPisIntegral(scip, ub - lb) )
continue;
/* check if bounds are shiftable */
if( !SCIPisEQ(scip, lb, 0.0) && /* lower bound != 0.0 */
SCIPisLT(scip, ub, SCIPinfinity(scip)) && /* upper bound != infinity */
SCIPisGT(scip, lb, -SCIPinfinity(scip)) && /* lower bound != -infinity */
#if 0
SCIPisLT(scip, ub - lb, SCIPinfinity(scip)) && /* interval length less than SCIPinfinity(scip) */
#endif
SCIPisLT(scip, ub - lb, (SCIP_Real) presoldata->maxshift) ) /* less than max shifting */
{
SCIP_VAR* newvar;
char newvarname[SCIP_MAXSTRLEN];
SCIP_Bool infeasible;
SCIP_Bool redundant;
SCIP_Bool aggregated;
SCIPdebugMessage("convert range <%s>[%g,%g] to [%g,%g]\n", SCIPvarGetName(var), lb, ub, 0.0, (ub - lb) );
/* create new variable */
(void) SCIPsnprintf(newvarname, SCIP_MAXSTRLEN, "%s_shift", SCIPvarGetName(var));
SCIP_CALL( SCIPcreateVar(scip, &newvar, newvarname, 0.0, (ub - lb), 0.0, SCIPvarGetType(var),
SCIPvarIsInitial(var), SCIPvarIsRemovable(var), NULL, NULL, NULL, NULL, NULL) );
SCIP_CALL( SCIPaddVar(scip, newvar) );
/* aggregate old variable with new variable */
if( presoldata->flipping )
{
if( REALABS(ub) < REALABS(lb) )
{
SCIP_CALL( SCIPaggregateVars(scip, var, newvar, 1.0, 1.0, ub, &infeasible, &redundant, &aggregated) );
}
else
{
SCIP_CALL( SCIPaggregateVars(scip, var, newvar, 1.0, -1.0, lb, &infeasible, &redundant, &aggregated) );
}
}
else
{
SCIP_CALL( SCIPaggregateVars(scip, var, newvar, 1.0, -1.0, lb, &infeasible, &redundant, &aggregated) );
}
assert(!infeasible);
assert(redundant);
assert(aggregated);
SCIPdebugMessage("var <%s> with bounds [%f,%f] has obj %f\n",
SCIPvarGetName(newvar),SCIPvarGetLbGlobal(newvar),SCIPvarGetUbGlobal(newvar),SCIPvarGetObj(newvar));
/* release variable */
SCIP_CALL( SCIPreleaseVar(scip, &newvar) );
/* take care of statistic */
(*naggrvars)++;
*result = SCIP_SUCCESS;
}
}
/* free temporary memory */
SCIPfreeBufferArray(scip, &vars);
return SCIP_OKAY;
}
/** creates a separator */
SCIP_RETCODE SCIPsepaCreate(
SCIP_SEPA** sepa, /**< pointer to separator data structure */
SCIP_SET* set, /**< global SCIP settings */
SCIP_MESSAGEHDLR* messagehdlr, /**< message handler */
BMS_BLKMEM* blkmem, /**< block memory for parameter settings */
const char* name, /**< name of separator */
const char* desc, /**< description of separator */
int priority, /**< priority of separator (>= 0: before, < 0: after constraint handlers) */
int freq, /**< frequency for calling separator */
SCIP_Real maxbounddist, /**< maximal relative distance from current node's dual bound to primal bound compared
* to best node's dual bound for applying separation */
SCIP_Bool usessubscip, /**< does the separator use a secondary SCIP instance? */
SCIP_Bool delay, /**< should separator be delayed, if other separators found cuts? */
SCIP_DECL_SEPACOPY ((*sepacopy)), /**< copy method of separator or NULL if you don't want to copy your plugin into sub-SCIPs */
SCIP_DECL_SEPAFREE ((*sepafree)), /**< destructor of separator */
SCIP_DECL_SEPAINIT ((*sepainit)), /**< initialize separator */
SCIP_DECL_SEPAEXIT ((*sepaexit)), /**< deinitialize separator */
SCIP_DECL_SEPAINITSOL ((*sepainitsol)), /**< solving process initialization method of separator */
SCIP_DECL_SEPAEXITSOL ((*sepaexitsol)), /**< solving process deinitialization method of separator */
SCIP_DECL_SEPAEXECLP ((*sepaexeclp)), /**< LP solution separation method of separator */
SCIP_DECL_SEPAEXECSOL ((*sepaexecsol)), /**< arbitrary primal solution separation method of separator */
SCIP_SEPADATA* sepadata /**< separator data */
)
{
char paramname[SCIP_MAXSTRLEN];
char paramdesc[SCIP_MAXSTRLEN];
assert(sepa != NULL);
assert(name != NULL);
assert(desc != NULL);
assert(freq >= -1);
assert(0.0 <= maxbounddist && maxbounddist <= 1.0);
assert(sepaexeclp != NULL || sepaexecsol != NULL);
SCIP_ALLOC( BMSallocMemory(sepa) );
SCIP_ALLOC( BMSduplicateMemoryArray(&(*sepa)->name, name, strlen(name)+1) );
SCIP_ALLOC( BMSduplicateMemoryArray(&(*sepa)->desc, desc, strlen(desc)+1) );
(*sepa)->priority = priority;
(*sepa)->freq = freq;
(*sepa)->maxbounddist = maxbounddist;
(*sepa)->usessubscip = usessubscip;
(*sepa)->sepacopy = sepacopy;
(*sepa)->sepafree = sepafree;
(*sepa)->sepainit = sepainit;
(*sepa)->sepaexit = sepaexit;
(*sepa)->sepainitsol = sepainitsol;
(*sepa)->sepaexitsol = sepaexitsol;
(*sepa)->sepaexeclp = sepaexeclp;
(*sepa)->sepaexecsol = sepaexecsol;
(*sepa)->sepadata = sepadata;
SCIP_CALL( SCIPclockCreate(&(*sepa)->setuptime, SCIP_CLOCKTYPE_DEFAULT) );
SCIP_CALL( SCIPclockCreate(&(*sepa)->sepaclock, SCIP_CLOCKTYPE_DEFAULT) );
(*sepa)->lastsepanode = -1;
(*sepa)->ncalls = 0;
(*sepa)->ncutoffs = 0;
(*sepa)->ncutsfound = 0;
(*sepa)->ncutsapplied = 0;
(*sepa)->nconssfound = 0;
(*sepa)->ndomredsfound = 0;
(*sepa)->ncallsatnode = 0;
(*sepa)->ncutsfoundatnode = 0;
(*sepa)->lpwasdelayed = FALSE;
(*sepa)->solwasdelayed = FALSE;
(*sepa)->initialized = FALSE;
/* add parameters */
(void) SCIPsnprintf(paramname, SCIP_MAXSTRLEN, "separating/%s/priority", name);
(void) SCIPsnprintf(paramdesc, SCIP_MAXSTRLEN, "priority of separator <%s>", name);
SCIP_CALL( SCIPsetAddIntParam(set, messagehdlr, blkmem, paramname, paramdesc,
&(*sepa)->priority, TRUE, priority, INT_MIN/4, INT_MAX/4,
paramChgdSepaPriority, (SCIP_PARAMDATA*)(*sepa)) ); /*lint !e740*/
(void) SCIPsnprintf(paramname, SCIP_MAXSTRLEN, "separating/%s/freq", name);
(void) SCIPsnprintf(paramdesc, SCIP_MAXSTRLEN, "frequency for calling separator <%s> (-1: never, 0: only in root node)", name);
SCIP_CALL( SCIPsetAddIntParam(set, messagehdlr, blkmem, paramname, paramdesc,
&(*sepa)->freq, FALSE, freq, -1, INT_MAX, NULL, NULL) );
(void) SCIPsnprintf(paramname, SCIP_MAXSTRLEN, "separating/%s/maxbounddist", name);
(void) SCIPsnprintf(paramdesc, SCIP_MAXSTRLEN, "maximal relative distance from current node's dual bound to primal bound compared to best node's dual bound for applying separator <%s> (0.0: only on current best node, 1.0: on all nodes)",
name);
SCIP_CALL( SCIPsetAddRealParam(set, messagehdlr, blkmem, paramname, paramdesc,
&(*sepa)->maxbounddist, TRUE, maxbounddist, 0.0, 1.0, NULL, NULL) );
(void) SCIPsnprintf(paramname, SCIP_MAXSTRLEN, "separating/%s/delay", name);
SCIP_CALL( SCIPsetAddBoolParam(set, messagehdlr, blkmem, paramname,
"should separator be delayed, if other separators found cuts?",
&(*sepa)->delay, TRUE, delay, NULL, NULL) ); /*lint !e740*/
return SCIP_OKAY;
}
/* Read SAT formula in "CNF File Format".
*
* The specification is taken from the
*
* Satisfiability Suggested Format
*
* Online available at http://www.intellektik.informatik.tu-darmstadt.de/SATLIB/Benchmarks/SAT/satformat.ps
*
* The method reads all files of CNF format. Other formats (SAT, SATX, SATE) are not supported.
*/
static
SCIP_RETCODE readCnf(
SCIP* scip, /**< SCIP data structure */
SCIP_FILE* file /**< input file */
)
{
SCIP_RETCODE retcode;
SCIP_VAR** vars;
SCIP_VAR** clausevars;
SCIP_CONS* cons;
int* varsign;
char* tok;
char* nexttok;
char line[MAXLINELEN];
char format[SCIP_MAXSTRLEN];
char varname[SCIP_MAXSTRLEN];
char s[SCIP_MAXSTRLEN];
SCIP_Bool dynamicconss;
SCIP_Bool dynamiccols;
SCIP_Bool dynamicrows;
SCIP_Bool useobj;
int linecount;
int clauselen;
int clausenum;
int nvars;
int nclauses;
int varnum;
int v;
assert(scip != NULL);
assert(file != NULL);
retcode = SCIP_OKAY;
linecount = 0;
/* read header */
SCIP_CALL( readCnfLine(scip, file, line, (int) sizeof(line), &linecount) );
if( *line != 'p' )
{
readError(scip, linecount, "problem declaration line expected");
return SCIP_READERROR;
}
if( sscanf(line, "p %8s %d %d", format, &nvars, &nclauses) != 3 )
{
readError(scip, linecount, "invalid problem declaration (must be 'p cnf <nvars> <nclauses>')");
return SCIP_READERROR;
}
if( strcmp(format, "cnf") != 0 )
{
(void) SCIPsnprintf(s, SCIP_MAXSTRLEN, "invalid format tag <%s> (must be 'cnf')", format);
readError(scip, linecount, s);
return SCIP_READERROR;
}
if( nvars <= 0 )
{
(void) SCIPsnprintf(s, SCIP_MAXSTRLEN, "invalid number of variables <%d> (must be positive)", nvars);
readError(scip, linecount, s);
return SCIP_READERROR;
}
if( nclauses <= 0 )
{
(void) SCIPsnprintf(s, SCIP_MAXSTRLEN, "invalid number of clauses <%d> (must be positive)", nclauses);
readError(scip, linecount, s);
return SCIP_READERROR;
}
/* get parameter values */
SCIP_CALL( SCIPgetBoolParam(scip, "reading/cnfreader/dynamicconss", &dynamicconss) );
SCIP_CALL( SCIPgetBoolParam(scip, "reading/cnfreader/dynamiccols", &dynamiccols) );
SCIP_CALL( SCIPgetBoolParam(scip, "reading/cnfreader/dynamicrows", &dynamicrows) );
SCIP_CALL( SCIPgetBoolParam(scip, "reading/cnfreader/useobj", &useobj) );
/* get temporary memory */
SCIP_CALL( SCIPallocBufferArray(scip, &vars, nvars) );
SCIP_CALL( SCIPallocBufferArray(scip, &clausevars, nvars) );
SCIP_CALL( SCIPallocBufferArray(scip, &varsign, nvars) );
/* create the variables */
for( v = 0; v < nvars; ++v )
{
(void) SCIPsnprintf(varname, SCIP_MAXSTRLEN, "x%d", v+1);
SCIP_CALL( SCIPcreateVar(scip, &vars[v], varname, 0.0, 1.0, 0.0, SCIP_VARTYPE_BINARY, !dynamiccols, dynamiccols,
NULL, NULL, NULL, NULL, NULL) );
SCIP_CALL( SCIPaddVar(scip, vars[v]) );
varsign[v] = 0;
}
/* read clauses */
clausenum = 0;
clauselen = 0;
do
{
retcode = readCnfLine(scip, file, line, (int) sizeof(line), &linecount);
if( retcode != SCIP_OKAY )
goto TERMINATE;
if( *line != '\0' && *line != '%' )
{
tok = SCIPstrtok(line, " \f\n\r\t", &nexttok);
while( tok != NULL )
{
/* parse literal and check for errors */
if( sscanf(tok, "%d", &v) != 1 )
{
(void) SCIPsnprintf(s, SCIP_MAXSTRLEN, "invalid literal <%s>", tok);
readError(scip, linecount, s);
retcode = SCIP_READERROR;
goto TERMINATE;
}
/* interpret literal number: v == 0: end of clause, v < 0: negated literal, v > 0: positive literal */
if( v == 0 )
{
/* end of clause: construct clause and add it to SCIP */
if( clauselen == 0 )
readWarning(scip, linecount, "empty clause detected in line -- problem infeasible");
clausenum++;
(void) SCIPsnprintf(s, SCIP_MAXSTRLEN, "c%d", clausenum);
if( SCIPfindConshdlr(scip, "logicor") != NULL )
{
/* if the constraint handler logicor exit create a logicor constraint */
SCIP_CALL( SCIPcreateConsLogicor(scip, &cons, s, clauselen, clausevars,
!dynamicrows, TRUE, TRUE, TRUE, TRUE, FALSE, FALSE, dynamicconss, dynamicrows, FALSE) );
}
else if( SCIPfindConshdlr(scip, "setppc") != NULL )
{
/* if the constraint handler logicor does not exit but constraint
* handler setppc create a setppc constraint */
SCIP_CALL( SCIPcreateConsSetcover(scip, &cons, s, clauselen, clausevars,
!dynamicrows, TRUE, TRUE, TRUE, TRUE, FALSE, FALSE, dynamicconss, dynamicrows, FALSE) );
}
else
{
/* if none of the previous constraint handler exits create a linear
* constraint */
SCIP_Real* vals;
int i;
SCIP_CALL( SCIPallocBufferArray(scip, &vals, clauselen) );
for( i = 0; i < clauselen; ++i )
vals[i] = 1.0;
SCIP_CALL( SCIPcreateConsLinear(scip, &cons, s, clauselen, clausevars, vals, 1.0, SCIPinfinity(scip),
!dynamicrows, TRUE, TRUE, TRUE, TRUE, FALSE, FALSE, dynamicconss, dynamicrows, FALSE) );
SCIPfreeBufferArray(scip, &vals);
}
SCIP_CALL( SCIPaddCons(scip, cons) );
SCIP_CALL( SCIPreleaseCons(scip, &cons) );
clauselen = 0;
}
else if( v >= -nvars && v <= nvars )
{
if( clauselen >= nvars )
{
readError(scip, linecount, "too many literals in clause");
retcode = SCIP_READERROR;
goto TERMINATE;
}
/* add literal to clause */
varnum = ABS(v)-1;
if( v < 0 )
{
SCIP_CALL( SCIPgetNegatedVar(scip, vars[varnum], &clausevars[clauselen]) );
varsign[varnum]--;
}
else
{
clausevars[clauselen] = vars[varnum];
varsign[varnum]++;
}
clauselen++;
}
else
{
(void) SCIPsnprintf(s, SCIP_MAXSTRLEN, "invalid variable number <%d>", ABS(v));
readError(scip, linecount, s);
retcode = SCIP_READERROR;
goto TERMINATE;
}
/* get next token */
tok = SCIPstrtok(NULL, " \f\n\r\t", &nexttok);
}
}
}
while( *line != '\0' && *line != '%' );
/* check for additional literals */
if( clauselen > 0 )
{
SCIPwarningMessage(scip, "found %d additional literals after last clause\n", clauselen);
}
/* check number of clauses */
if( clausenum != nclauses )
{
SCIPwarningMessage(scip, "expected %d clauses, but found %d\n", nclauses, clausenum);
}
TERMINATE:
/* change objective values and release variables */
SCIP_CALL( SCIPsetObjsense(scip, SCIP_OBJSENSE_MAXIMIZE) );
if( useobj )
{
for( v = 0; v < nvars; ++v )
{
SCIP_CALL( SCIPchgVarObj(scip, vars[v], (SCIP_Real)varsign[v]) );
SCIP_CALL( SCIPreleaseVar(scip, &vars[v]) );
}
}
/* free temporary memory */
SCIPfreeBufferArray(scip, &varsign);
SCIPfreeBufferArray(scip, &clausevars);
SCIPfreeBufferArray(scip, &vars);
return retcode;
}
/** execution method of primal heuristic */
static
SCIP_DECL_HEUREXEC(heurExecMutation)
{ /*lint --e{715}*/
SCIP_Longint maxnnodes;
SCIP_Longint nsubnodes; /* node limit for the subproblem */
SCIP_HEURDATA* heurdata; /* heuristic's data */
SCIP* subscip; /* the subproblem created by mutation */
SCIP_VAR** vars; /* original problem's variables */
SCIP_VAR** subvars; /* subproblem's variables */
SCIP_HASHMAP* varmapfw; /* mapping of SCIP variables to sub-SCIP variables */
SCIP_Real cutoff; /* objective cutoff for the subproblem */
SCIP_Real maxnnodesr;
SCIP_Real memorylimit;
SCIP_Real timelimit; /* timelimit for the subproblem */
SCIP_Real upperbound;
int nvars; /* number of original problem's variables */
int i;
SCIP_Bool success;
SCIP_RETCODE retcode;
assert( heur != NULL );
assert( scip != NULL );
assert( result != NULL );
/* get heuristic's data */
heurdata = SCIPheurGetData(heur);
assert( heurdata != NULL );
*result = SCIP_DELAYED;
/* only call heuristic, if feasible solution is available */
if( SCIPgetNSols(scip) <= 0 )
return SCIP_OKAY;
/* only call heuristic, if the best solution comes from transformed problem */
assert( SCIPgetBestSol(scip) != NULL );
if( SCIPsolIsOriginal(SCIPgetBestSol(scip)) )
return SCIP_OKAY;
/* only call heuristic, if enough nodes were processed since last incumbent */
if( SCIPgetNNodes(scip) - SCIPgetSolNodenum(scip,SCIPgetBestSol(scip)) < heurdata->nwaitingnodes)
return SCIP_OKAY;
*result = SCIP_DIDNOTRUN;
/* only call heuristic, if discrete variables are present */
if( SCIPgetNBinVars(scip) == 0 && SCIPgetNIntVars(scip) == 0 )
return SCIP_OKAY;
/* calculate the maximal number of branching nodes until heuristic is aborted */
maxnnodesr = heurdata->nodesquot * SCIPgetNNodes(scip);
/* reward mutation if it succeeded often, count the setup costs for the sub-MIP as 100 nodes */
maxnnodesr *= 1.0 + 2.0 * (SCIPheurGetNBestSolsFound(heur)+1.0)/(SCIPheurGetNCalls(heur) + 1.0);
maxnnodes = (SCIP_Longint) maxnnodesr - 100 * SCIPheurGetNCalls(heur);
maxnnodes += heurdata->nodesofs;
/* determine the node limit for the current process */
nsubnodes = maxnnodes - heurdata->usednodes;
nsubnodes = MIN(nsubnodes, heurdata->maxnodes);
/* check whether we have enough nodes left to call subproblem solving */
if( nsubnodes < heurdata->minnodes )
return SCIP_OKAY;
if( SCIPisStopped(scip) )
return SCIP_OKAY;
*result = SCIP_DIDNOTFIND;
SCIP_CALL( SCIPgetVarsData(scip, &vars, &nvars, NULL, NULL, NULL, NULL) );
/* initializing the subproblem */
SCIP_CALL( SCIPallocBufferArray(scip, &subvars, nvars) );
SCIP_CALL( SCIPcreate(&subscip) );
/* create the variable mapping hash map */
SCIP_CALL( SCIPhashmapCreate(&varmapfw, SCIPblkmem(subscip), SCIPcalcHashtableSize(5 * nvars)) );
if( heurdata->uselprows )
{
char probname[SCIP_MAXSTRLEN];
/* copy all plugins */
SCIP_CALL( SCIPincludeDefaultPlugins(subscip) );
/* get name of the original problem and add the string "_mutationsub" */
(void) SCIPsnprintf(probname, SCIP_MAXSTRLEN, "%s_mutationsub", SCIPgetProbName(scip));
/* create the subproblem */
SCIP_CALL( SCIPcreateProb(subscip, probname, NULL, NULL, NULL, NULL, NULL, NULL, NULL) );
/* copy all variables */
SCIP_CALL( SCIPcopyVars(scip, subscip, varmapfw, NULL, TRUE) );
}
else
{
SCIP_Bool valid;
valid = FALSE;
SCIP_CALL( SCIPcopy(scip, subscip, varmapfw, NULL, "rens", TRUE, FALSE, TRUE, &valid) );
if( heurdata->copycuts )
{
/* copies all active cuts from cutpool of sourcescip to linear constraints in targetscip */
SCIP_CALL( SCIPcopyCuts(scip, subscip, varmapfw, NULL, TRUE, NULL) );
}
SCIPdebugMessage("Copying the SCIP instance was %s complete.\n", valid ? "" : "not ");
}
for( i = 0; i < nvars; i++ )
subvars[i] = (SCIP_VAR*) SCIPhashmapGetImage(varmapfw, vars[i]);
/* free hash map */
SCIPhashmapFree(&varmapfw);
/* create a new problem, which fixes variables with same value in bestsol and LP relaxation */
SCIP_CALL( createSubproblem(scip, subscip, subvars, heurdata->minfixingrate, &heurdata->randseed, heurdata->uselprows) );
/* do not abort subproblem on CTRL-C */
SCIP_CALL( SCIPsetBoolParam(subscip, "misc/catchctrlc", FALSE) );
/* disable output to console */
SCIP_CALL( SCIPsetIntParam(subscip, "display/verblevel", 0) );
/* check whether there is enough time and memory left */
SCIP_CALL( SCIPgetRealParam(scip, "limits/time", &timelimit) );
if( !SCIPisInfinity(scip, timelimit) )
timelimit -= SCIPgetSolvingTime(scip);
SCIP_CALL( SCIPgetRealParam(scip, "limits/memory", &memorylimit) );
/* substract the memory already used by the main SCIP and the estimated memory usage of external software */
if( !SCIPisInfinity(scip, memorylimit) )
{
memorylimit -= SCIPgetMemUsed(scip)/1048576.0;
memorylimit -= SCIPgetMemExternEstim(scip)/1048576.0;
}
/* abort if no time is left or not enough memory to create a copy of SCIP, including external memory usage */
if( timelimit <= 0.0 || memorylimit <= 2.0*SCIPgetMemExternEstim(scip)/1048576.0 )
goto TERMINATE;
/* set limits for the subproblem */
SCIP_CALL( SCIPsetLongintParam(subscip, "limits/nodes", nsubnodes) );
SCIP_CALL( SCIPsetRealParam(subscip, "limits/time", timelimit) );
SCIP_CALL( SCIPsetRealParam(subscip, "limits/memory", memorylimit) );
/* forbid recursive call of heuristics and separators solving subMIPs */
SCIP_CALL( SCIPsetSubscipsOff(subscip, TRUE) );
/* disable cutting plane separation */
SCIP_CALL( SCIPsetSeparating(subscip, SCIP_PARAMSETTING_OFF, TRUE) );
/* disable expensive presolving */
SCIP_CALL( SCIPsetPresolving(subscip, SCIP_PARAMSETTING_FAST, TRUE) );
/* use best estimate node selection */
if( SCIPfindNodesel(subscip, "estimate") != NULL && !SCIPisParamFixed(subscip, "nodeselection/estimate/stdpriority") )
{
SCIP_CALL( SCIPsetIntParam(subscip, "nodeselection/estimate/stdpriority", INT_MAX/4) );
}
/* use inference branching */
if( SCIPfindBranchrule(subscip, "inference") != NULL && !SCIPisParamFixed(subscip, "branching/inference/priority") )
{
SCIP_CALL( SCIPsetIntParam(subscip, "branching/inference/priority", INT_MAX/4) );
}
/* disable conflict analysis */
if( !SCIPisParamFixed(subscip, "conflict/useprop") )
{
SCIP_CALL( SCIPsetBoolParam(subscip, "conflict/useprop", FALSE) );
}
if( !SCIPisParamFixed(subscip, "conflict/useinflp") )
{
SCIP_CALL( SCIPsetBoolParam(subscip, "conflict/useinflp", FALSE) );
}
if( !SCIPisParamFixed(subscip, "conflict/useboundlp") )
{
SCIP_CALL( SCIPsetBoolParam(subscip, "conflict/useboundlp", FALSE) );
}
if( !SCIPisParamFixed(subscip, "conflict/usesb") )
{
SCIP_CALL( SCIPsetBoolParam(subscip, "conflict/usesb", FALSE) );
}
if( !SCIPisParamFixed(subscip, "conflict/usepseudo") )
{
SCIP_CALL( SCIPsetBoolParam(subscip, "conflict/usepseudo", FALSE) );
}
/* employ a limit on the number of enforcement rounds in the quadratic constraint handlers; this fixes the issue that
* sometimes the quadratic constraint handler needs hundreds or thousands of enforcement rounds to determine the
* feasibility status of a single node without fractional branching candidates by separation (namely for uflquad
* instances); however, the solution status of the sub-SCIP might get corrupted by this; hence no decutions shall be
* made for the original SCIP
*/
if( SCIPfindConshdlr(subscip, "quadratic") != NULL && !SCIPisParamFixed(subscip, "constraints/quadratic/enfolplimit") )
{
SCIP_CALL( SCIPsetIntParam(subscip, "constraints/quadratic/enfolplimit", 10) );
}
/* add an objective cutoff */
cutoff = SCIPinfinity(scip);
assert( !SCIPisInfinity(scip, SCIPgetUpperbound(scip)) );
upperbound = SCIPgetUpperbound(scip) - SCIPsumepsilon(scip);
if( !SCIPisInfinity(scip, -1.0 * SCIPgetLowerbound(scip)) )
{
cutoff = (1-heurdata->minimprove) * SCIPgetUpperbound(scip) + heurdata->minimprove * SCIPgetLowerbound(scip);
}
else
{
if( SCIPgetUpperbound ( scip ) >= 0 )
cutoff = ( 1 - heurdata->minimprove ) * SCIPgetUpperbound ( scip );
else
cutoff = ( 1 + heurdata->minimprove ) * SCIPgetUpperbound ( scip );
}
cutoff = MIN(upperbound, cutoff );
SCIP_CALL( SCIPsetObjlimit(subscip, cutoff) );
/* solve the subproblem */
SCIPdebugMessage("Solve Mutation subMIP\n");
retcode = SCIPsolve(subscip);
/* Errors in solving the subproblem should not kill the overall solving process
* Hence, the return code is caught and a warning is printed, only in debug mode, SCIP will stop.
*/
if( retcode != SCIP_OKAY )
{
#ifndef NDEBUG
SCIP_CALL( retcode );
#endif
SCIPwarningMessage(scip, "Error while solving subproblem in Mutation heuristic; sub-SCIP terminated with code <%d>\n",retcode);
}
heurdata->usednodes += SCIPgetNNodes(subscip);
/* check, whether a solution was found */
if( SCIPgetNSols(subscip) > 0 )
{
SCIP_SOL** subsols;
int nsubsols;
/* check, whether a solution was found;
* due to numerics, it might happen that not all solutions are feasible -> try all solutions until one was accepted
*/
nsubsols = SCIPgetNSols(subscip);
subsols = SCIPgetSols(subscip);
success = FALSE;
for( i = 0; i < nsubsols && !success; ++i )
{
SCIP_CALL( createNewSol(scip, subscip, subvars, heur, subsols[i], &success) );
}
if( success )
*result = SCIP_FOUNDSOL;
}
TERMINATE:
/* free subproblem */
SCIPfreeBufferArray(scip, &subvars);
SCIP_CALL( SCIPfree(&subscip) );
return SCIP_OKAY;
}
/** LP solution separation method of separator */
static
SCIP_DECL_SEPAEXECLP(sepaExeclpGomory)
{ /*lint --e{715}*/
SCIP_SEPADATA* sepadata;
SCIP_VAR** vars;
SCIP_COL** cols;
SCIP_ROW** rows;
SCIP_Real* binvrow;
SCIP_Real* cutcoefs;
SCIP_Real maxscale;
SCIP_Real minfrac;
SCIP_Real maxfrac;
SCIP_Longint maxdnom;
SCIP_Bool cutoff;
int* basisind;
int naddedcuts;
int nvars;
int ncols;
int nrows;
int ncalls;
int depth;
int maxdepth;
int maxsepacuts;
int c;
int i;
assert(sepa != NULL);
assert(strcmp(SCIPsepaGetName(sepa), SEPA_NAME) == 0);
assert(scip != NULL);
assert(result != NULL);
*result = SCIP_DIDNOTRUN;
sepadata = SCIPsepaGetData(sepa);
assert(sepadata != NULL);
depth = SCIPgetDepth(scip);
ncalls = SCIPsepaGetNCallsAtNode(sepa);
minfrac = sepadata->away;
maxfrac = 1.0 - sepadata->away;
/* only call separator, if we are not close to terminating */
if( SCIPisStopped(scip) )
return SCIP_OKAY;
/* only call the gomory cut separator a given number of times at each node */
if( (depth == 0 && sepadata->maxroundsroot >= 0 && ncalls >= sepadata->maxroundsroot)
|| (depth > 0 && sepadata->maxrounds >= 0 && ncalls >= sepadata->maxrounds) )
return SCIP_OKAY;
/* only call separator, if an optimal LP solution is at hand */
if( SCIPgetLPSolstat(scip) != SCIP_LPSOLSTAT_OPTIMAL )
return SCIP_OKAY;
/* only call separator, if the LP solution is basic */
if( !SCIPisLPSolBasic(scip) )
return SCIP_OKAY;
/* only call separator, if there are fractional variables */
if( SCIPgetNLPBranchCands(scip) == 0 )
return SCIP_OKAY;
/* get variables data */
SCIP_CALL( SCIPgetVarsData(scip, &vars, &nvars, NULL, NULL, NULL, NULL) );
/* get LP data */
SCIP_CALL( SCIPgetLPColsData(scip, &cols, &ncols) );
SCIP_CALL( SCIPgetLPRowsData(scip, &rows, &nrows) );
if( ncols == 0 || nrows == 0 )
return SCIP_OKAY;
#if 0 /* if too many columns, separator is usually very slow: delay it until no other cuts have been found */
if( ncols >= 50*nrows )
return SCIP_OKAY;
if( ncols >= 5*nrows )
{
int ncutsfound;
ncutsfound = SCIPgetNCutsFound(scip);
if( ncutsfound > sepadata->lastncutsfound || !SCIPsepaWasLPDelayed(sepa) )
{
sepadata->lastncutsfound = ncutsfound;
*result = SCIP_DELAYED;
return SCIP_OKAY;
}
}
#endif
/* set the maximal denominator in rational representation of gomory cut and the maximal scale factor to
* scale resulting cut to integral values to avoid numerical instabilities
*/
/**@todo find better but still stable gomory cut settings: look at dcmulti, gesa3, khb0525, misc06, p2756 */
maxdepth = SCIPgetMaxDepth(scip);
if( depth == 0 )
{
maxdnom = 1000;
maxscale = 1000.0;
}
else if( depth <= maxdepth/4 )
{
maxdnom = 1000;
maxscale = 1000.0;
}
else if( depth <= maxdepth/2 )
{
maxdnom = 100;
maxscale = 100.0;
}
else
{
maxdnom = 10;
maxscale = 10.0;
}
/* allocate temporary memory */
SCIP_CALL( SCIPallocBufferArray(scip, &cutcoefs, nvars) );
SCIP_CALL( SCIPallocBufferArray(scip, &basisind, nrows) );
SCIP_CALL( SCIPallocBufferArray(scip, &binvrow, nrows) );
/* get basis indices */
SCIP_CALL( SCIPgetLPBasisInd(scip, basisind) );
/* get the maximal number of cuts allowed in a separation round */
if( depth == 0 )
maxsepacuts = sepadata->maxsepacutsroot;
else
maxsepacuts = sepadata->maxsepacuts;
SCIPdebugMessage("searching gomory cuts: %d cols, %d rows, maxdnom=%"SCIP_LONGINT_FORMAT", maxscale=%g, maxcuts=%d\n",
ncols, nrows, maxdnom, maxscale, maxsepacuts);
cutoff = FALSE;
naddedcuts = 0;
/* for all basic columns belonging to integer variables, try to generate a gomory cut */
for( i = 0; i < nrows && naddedcuts < maxsepacuts && !SCIPisStopped(scip) && !cutoff; ++i )
{
SCIP_Bool tryrow;
tryrow = FALSE;
c = basisind[i];
if( c >= 0 )
{
SCIP_VAR* var;
assert(c < ncols);
var = SCIPcolGetVar(cols[c]);
if( SCIPvarGetType(var) != SCIP_VARTYPE_CONTINUOUS )
{
SCIP_Real primsol;
primsol = SCIPcolGetPrimsol(cols[c]);
assert(SCIPgetVarSol(scip, var) == primsol); /*lint !e777*/
if( SCIPfeasFrac(scip, primsol) >= minfrac )
{
SCIPdebugMessage("trying gomory cut for col <%s> [%g]\n", SCIPvarGetName(var), primsol);
tryrow = TRUE;
}
}
}
else if( sepadata->separaterows )
{
SCIP_ROW* row;
assert(0 <= -c-1 && -c-1 < nrows);
row = rows[-c-1];
if( SCIProwIsIntegral(row) && !SCIProwIsModifiable(row) )
{
SCIP_Real primsol;
primsol = SCIPgetRowActivity(scip, row);
if( SCIPfeasFrac(scip, primsol) >= minfrac )
{
SCIPdebugMessage("trying gomory cut for row <%s> [%g]\n", SCIProwGetName(row), primsol);
tryrow = TRUE;
}
}
}
if( tryrow )
{
SCIP_Real cutrhs;
SCIP_Real cutact;
SCIP_Bool success;
SCIP_Bool cutislocal;
/* get the row of B^-1 for this basic integer variable with fractional solution value */
SCIP_CALL( SCIPgetLPBInvRow(scip, i, binvrow) );
cutact = 0.0;
cutrhs = SCIPinfinity(scip);
/* create a MIR cut out of the weighted LP rows using the B^-1 row as weights */
SCIP_CALL( SCIPcalcMIR(scip, NULL, BOUNDSWITCH, USEVBDS, ALLOWLOCAL, FIXINTEGRALRHS, NULL, NULL,
(int) MAXAGGRLEN(nvars), sepadata->maxweightrange, minfrac, maxfrac,
binvrow, 1.0, NULL, NULL, cutcoefs, &cutrhs, &cutact, &success, &cutislocal) );
assert(ALLOWLOCAL || !cutislocal);
/* @todo Currently we are using the SCIPcalcMIR() function to compute the coefficients of the Gomory
* cut. Alternatively, we could use the direct version (see thesis of Achterberg formula (8.4)) which
* leads to cut a of the form \sum a_i x_i \geq 1. Rumor has it that these cuts are better.
*/
SCIPdebugMessage(" -> success=%u: %g <= %g\n", success, cutact, cutrhs);
/* if successful, convert dense cut into sparse row, and add the row as a cut */
if( success && SCIPisFeasGT(scip, cutact, cutrhs) )
{
SCIP_ROW* cut;
char cutname[SCIP_MAXSTRLEN];
int v;
/* construct cut name */
if( c >= 0 )
(void) SCIPsnprintf(cutname, SCIP_MAXSTRLEN, "gom%d_x%d", SCIPgetNLPs(scip), c);
else
(void) SCIPsnprintf(cutname, SCIP_MAXSTRLEN, "gom%d_s%d", SCIPgetNLPs(scip), -c-1);
/* create empty cut */
SCIP_CALL( SCIPcreateEmptyRowSepa(scip, &cut, sepa, cutname, -SCIPinfinity(scip), cutrhs,
cutislocal, FALSE, sepadata->dynamiccuts) );
/* cache the row extension and only flush them if the cut gets added */
SCIP_CALL( SCIPcacheRowExtensions(scip, cut) );
/* collect all non-zero coefficients */
for( v = 0; v < nvars; ++v )
{
if( !SCIPisZero(scip, cutcoefs[v]) )
{
SCIP_CALL( SCIPaddVarToRow(scip, cut, vars[v], cutcoefs[v]) );
}
}
if( SCIProwGetNNonz(cut) == 0 )
{
assert(SCIPisFeasNegative(scip, cutrhs));
SCIPdebugMessage(" -> gomory cut detected infeasibility with cut 0 <= %f\n", cutrhs);
cutoff = TRUE;
}
else if( SCIProwGetNNonz(cut) == 1 )
{
/* add the bound change as cut to avoid that the LP gets modified. that would mean the LP is not flushed
* and the method SCIPgetLPBInvRow() fails; SCIP internally will apply that bound change automatically
*/
SCIP_CALL( SCIPaddCut(scip, NULL, cut, TRUE) );
naddedcuts++;
}
else
{
/* Only take efficacious cuts, except for cuts with one non-zero coefficients (= bound
* changes); the latter cuts will be handeled internally in sepastore.
*/
if( SCIPisCutEfficacious(scip, NULL, cut) )
{
assert(success == TRUE);
SCIPdebugMessage(" -> gomory cut for <%s>: act=%f, rhs=%f, eff=%f\n",
c >= 0 ? SCIPvarGetName(SCIPcolGetVar(cols[c])) : SCIProwGetName(rows[-c-1]),
cutact, cutrhs, SCIPgetCutEfficacy(scip, NULL, cut));
if( sepadata->makeintegral )
{
/* try to scale the cut to integral values */
SCIP_CALL( SCIPmakeRowIntegral(scip, cut, -SCIPepsilon(scip), SCIPsumepsilon(scip),
maxdnom, maxscale, MAKECONTINTEGRAL, &success) );
if( sepadata->forcecuts )
success = TRUE;
/* in case the left hand side in minus infinity and the right hand side is plus infinity the cut is
* useless so we are not taking it at all
*/
if( (SCIPisInfinity(scip, -SCIProwGetLhs(cut)) && SCIPisInfinity(scip, SCIProwGetRhs(cut))) )
success = FALSE;
/* @todo Trying to make the Gomory cut integral might fail. Due to numerical reasons/arguments we
* currently ignore such cuts. If the cut, however, has small support (let's say smaller or equal to
* 5), we might want to add that cut (even it does not have integral coefficients). To be able to
* do that we need to add a rank to the data structure of a row. The rank of original rows are
* zero and for aggregated rows it is the maximum over all used rows plus one.
*/
}
if( success )
{
SCIPdebugMessage(" -> found gomory cut <%s>: act=%f, rhs=%f, norm=%f, eff=%f, min=%f, max=%f (range=%f)\n",
cutname, SCIPgetRowLPActivity(scip, cut), SCIProwGetRhs(cut), SCIProwGetNorm(cut),
SCIPgetCutEfficacy(scip, NULL, cut),
SCIPgetRowMinCoef(scip, cut), SCIPgetRowMaxCoef(scip, cut),
SCIPgetRowMaxCoef(scip, cut)/SCIPgetRowMinCoef(scip, cut));
/* flush all changes before adding the cut */
SCIP_CALL( SCIPflushRowExtensions(scip, cut) );
/* add global cuts which are not implicit bound changes to the cut pool */
if( !cutislocal )
{
if( sepadata->delayedcuts )
{
SCIP_CALL( SCIPaddDelayedPoolCut(scip, cut) );
}
else
{
SCIP_CALL( SCIPaddPoolCut(scip, cut) );
}
}
else
{
/* local cuts we add to the sepastore */
SCIP_CALL( SCIPaddCut(scip, NULL, cut, FALSE) );
}
naddedcuts++;
}
}
}
/* release the row */
SCIP_CALL( SCIPreleaseRow(scip, &cut) );
}
}
}
/* free temporary memory */
SCIPfreeBufferArray(scip, &binvrow);
SCIPfreeBufferArray(scip, &basisind);
SCIPfreeBufferArray(scip, &cutcoefs);
SCIPdebugMessage("end searching gomory cuts: found %d cuts\n", naddedcuts);
sepadata->lastncutsfound = SCIPgetNCutsFound(scip);
/* evalute the result of the separation */
if( cutoff )
*result = SCIP_CUTOFF;
else if ( naddedcuts > 0 )
*result = SCIP_SEPARATED;
else
*result = SCIP_DIDNOTFIND;
return SCIP_OKAY;
}
/** main procedure of the RENS heuristic, creates and solves a subMIP */
SCIP_RETCODE SCIPapplyGcgrens(
SCIP* scip, /**< original SCIP data structure */
SCIP_HEUR* heur, /**< heuristic data structure */
SCIP_RESULT* result, /**< result data structure */
SCIP_Real minfixingrate, /**< minimum percentage of integer variables that have to be fixed */
SCIP_Real minimprove, /**< factor by which RENS should at least improve the incumbent */
SCIP_Longint maxnodes, /**< maximum number of nodes for the subproblem */
SCIP_Longint nstallnodes, /**< number of stalling nodes for the subproblem */
SCIP_Bool binarybounds, /**< should general integers get binary bounds [floor(.),ceil(.)]? */
SCIP_Bool uselprows /**< should subproblem be created out of the rows in the LP rows? */
)
{
SCIP* subscip; /* the subproblem created by RENS */
SCIP_HASHMAP* varmapfw; /* mapping of SCIP variables to sub-SCIP variables */
SCIP_VAR** vars; /* original problem's variables */
SCIP_VAR** subvars; /* subproblem's variables */
SCIP_Real cutoff; /* objective cutoff for the subproblem */
SCIP_Real timelimit;
SCIP_Real memorylimit;
int nvars;
int i;
SCIP_Bool success;
SCIP_RETCODE retcode;
assert(scip != NULL);
assert(heur != NULL);
assert(result != NULL);
assert(maxnodes >= 0);
assert(nstallnodes >= 0);
assert(0.0 <= minfixingrate && minfixingrate <= 1.0);
assert(0.0 <= minimprove && minimprove <= 1.0);
SCIP_CALL( SCIPgetVarsData(scip, &vars, &nvars, NULL, NULL, NULL, NULL) );
/* initialize the subproblem */
SCIP_CALL( SCIPcreate(&subscip) );
/* create the variable mapping hash map */
SCIP_CALL( SCIPhashmapCreate(&varmapfw, SCIPblkmem(subscip), SCIPcalcHashtableSize(5 * nvars)) );
SCIP_CALL( SCIPallocBufferArray(scip, &subvars, nvars) );
if( uselprows )
{
char probname[SCIP_MAXSTRLEN];
/* copy all plugins */
SCIP_CALL( SCIPincludeDefaultPlugins(subscip) );
/* get name of the original problem and add the string "_gcgrenssub" */
(void) SCIPsnprintf(probname, SCIP_MAXSTRLEN, "%s_gcgrenssub", SCIPgetProbName(scip));
/* create the subproblem */
SCIP_CALL( SCIPcreateProb(subscip, probname, NULL, NULL, NULL, NULL, NULL, NULL, NULL) );
/* copy all variables */
SCIP_CALL( SCIPcopyVars(scip, subscip, varmapfw, NULL, TRUE) );
}
else
{
SCIP_Bool valid;
SCIP_HEURDATA* heurdata;
valid = FALSE;
SCIP_CALL( SCIPcopy(scip, subscip, varmapfw, NULL, "gcgrens", TRUE, FALSE, TRUE, &valid) ); /** @todo check for thread safeness */
/* get heuristic's data */
heurdata = SCIPheurGetData(heur);
assert( heurdata != NULL );
if( heurdata->copycuts )
{
/** copies all active cuts from cutpool of sourcescip to linear constraints in targetscip */
SCIP_CALL( SCIPcopyCuts(scip, subscip, varmapfw, NULL, TRUE, NULL) );
}
SCIPdebugMessage("Copying the SCIP instance was %s complete.\n", valid ? "" : "not ");
}
for( i = 0; i < nvars; i++ )
subvars[i] = (SCIP_VAR*) SCIPhashmapGetImage(varmapfw, vars[i]);
/* free hash map */
SCIPhashmapFree(&varmapfw);
/* create a new problem, which fixes variables with same value in bestsol and LP relaxation */
SCIP_CALL( createSubproblem(scip, subscip, subvars, minfixingrate, binarybounds, uselprows, &success) );
SCIPdebugMessage("RENS subproblem: %d vars, %d cons, success=%u\n", SCIPgetNVars(subscip), SCIPgetNConss(subscip), success);
/* do not abort subproblem on CTRL-C */
SCIP_CALL( SCIPsetBoolParam(subscip, "misc/catchctrlc", FALSE) );
/* disable output to console */
SCIP_CALL( SCIPsetIntParam(subscip, "display/verblevel", 0) );
/* check whether there is enough time and memory left */
timelimit = 0.0;
memorylimit = 0.0;
SCIP_CALL( SCIPgetRealParam(scip, "limits/time", &timelimit) );
if( !SCIPisInfinity(scip, timelimit) )
timelimit -= SCIPgetSolvingTime(scip);
SCIP_CALL( SCIPgetRealParam(scip, "limits/memory", &memorylimit) );
if( !SCIPisInfinity(scip, memorylimit) )
memorylimit -= SCIPgetMemUsed(scip)/1048576.0;
if( timelimit <= 0.0 || memorylimit <= 0.0 )
goto TERMINATE;
/* set limits for the subproblem */
SCIP_CALL( SCIPsetLongintParam(subscip, "limits/stallnodes", nstallnodes) );
SCIP_CALL( SCIPsetLongintParam(subscip, "limits/nodes", maxnodes) );
SCIP_CALL( SCIPsetRealParam(subscip, "limits/time", timelimit) );
SCIP_CALL( SCIPsetRealParam(subscip, "limits/memory", memorylimit) );
/* forbid recursive call of heuristics and separators solving sub-SCIPs */
SCIP_CALL( SCIPsetSubscipsOff(subscip, TRUE) );
/* disable cutting plane separation */
SCIP_CALL( SCIPsetSeparating(subscip, SCIP_PARAMSETTING_OFF, TRUE) );
/* disable expensive presolving */
SCIP_CALL( SCIPsetPresolving(subscip, SCIP_PARAMSETTING_FAST, TRUE) );
/* use best estimate node selection */
if( SCIPfindNodesel(scip, "estimate") != NULL )
{
SCIP_CALL( SCIPsetIntParam(subscip, "nodeselection/estimate/stdpriority", INT_MAX/4) );
}
/* use inference branching */
if( SCIPfindBranchrule(scip, "inference") != NULL )
{
SCIP_CALL( SCIPsetIntParam(subscip, "branching/inference/priority", INT_MAX/4) );
}
/* disable conflict analysis */
SCIP_CALL( SCIPsetBoolParam(subscip, "conflict/useprop", FALSE) );
SCIP_CALL( SCIPsetBoolParam(subscip, "conflict/useinflp", FALSE) );
SCIP_CALL( SCIPsetBoolParam(subscip, "conflict/useboundlp", FALSE) );
SCIP_CALL( SCIPsetBoolParam(subscip, "conflict/usesb", FALSE) );
SCIP_CALL( SCIPsetBoolParam(subscip, "conflict/usepseudo", FALSE) );
#ifdef SCIP_DEBUG
/* for debugging RENS, enable MIP output */
SCIP_CALL( SCIPsetIntParam(subscip, "display/verblevel", 5) );
SCIP_CALL( SCIPsetIntParam(subscip, "display/freq", 100000000) );
#endif
/* if the subproblem could not be created, free memory and return */
if( !success )
{
*result = SCIP_DIDNOTRUN;
SCIPfreeBufferArray(scip, &subvars);
SCIP_CALL( SCIPfree(&subscip) );
return SCIP_OKAY;
}
/* if there is already a solution, add an objective cutoff */
if( SCIPgetNSols(scip) > 0 )
{
SCIP_Real upperbound;
assert( !SCIPisInfinity(scip,SCIPgetUpperbound(scip)) );
upperbound = SCIPgetUpperbound(scip) - SCIPsumepsilon(scip);
if( !SCIPisInfinity(scip,-1.0*SCIPgetLowerbound(scip)) )
{
cutoff = (1-minimprove)*SCIPgetUpperbound(scip) + minimprove*SCIPgetLowerbound(scip);
}
else
{
if( SCIPgetUpperbound ( scip ) >= 0 )
cutoff = ( 1 - minimprove ) * SCIPgetUpperbound ( scip );
else
cutoff = ( 1 + minimprove ) * SCIPgetUpperbound ( scip );
}
cutoff = MIN(upperbound, cutoff);
SCIP_CALL( SCIPsetObjlimit(subscip, cutoff) );
}
/* presolve the subproblem */
retcode = SCIPpresolve(subscip);
/* Errors in solving the subproblem should not kill the overall solving process
* Hence, the return code is caught and a warning is printed, only in debug mode, SCIP will stop.
*/
if( retcode != SCIP_OKAY )
{
#ifndef NDEBUG
SCIP_CALL( retcode );
#endif
SCIPwarningMessage(scip, "Error while presolving subproblem in GCG RENS heuristic; sub-SCIP terminated with code <%d>\n",retcode);
}
SCIPdebugMessage("GCG RENS presolved subproblem: %d vars, %d cons, success=%u\n", SCIPgetNVars(subscip), SCIPgetNConss(subscip), success);
/* after presolving, we should have at least reached a certain fixing rate over ALL variables (including continuous)
* to ensure that not only the MIP but also the LP relaxation is easy enough
*/
if( ( nvars - SCIPgetNVars(subscip) ) / (SCIP_Real)nvars >= minfixingrate / 2.0 )
{
SCIP_SOL** subsols;
int nsubsols;
/* solve the subproblem */
SCIPdebugMessage("solving subproblem: nstallnodes=%"SCIP_LONGINT_FORMAT", maxnodes=%"SCIP_LONGINT_FORMAT"\n", nstallnodes, maxnodes);
retcode = SCIPsolve(subscip);
/* Errors in solving the subproblem should not kill the overall solving process
* Hence, the return code is caught and a warning is printed, only in debug mode, SCIP will stop.
*/
if( retcode != SCIP_OKAY )
{
#ifndef NDEBUG
SCIP_CALL( retcode );
#endif
SCIPwarningMessage(scip, "Error while solving subproblem in GCG RENS heuristic; sub-SCIP terminated with code <%d>\n",retcode);
}
/* check, whether a solution was found;
* due to numerics, it might happen that not all solutions are feasible -> try all solutions until one was accepted
*/
nsubsols = SCIPgetNSols(subscip);
subsols = SCIPgetSols(subscip);
success = FALSE;
for( i = 0; i < nsubsols && !success; ++i )
{
SCIP_CALL( createNewSol(scip, subscip, subvars, heur, subsols[i], &success) );
}
if( success )
*result = SCIP_FOUNDSOL;
}
TERMINATE:
/* free subproblem */
SCIPfreeBufferArray(scip, &subvars);
SCIP_CALL( SCIPfree(&subscip) );
return SCIP_OKAY;
}
int GamsScip::callSolver()
{
assert(gmo != NULL);
assert(gev != NULL);
assert(scip != NULL);
/* set interface type so we see =B= and =X= equations */
gmoInterfaceSet(gmo, gmoIFace_Raw);
if( gmoGetEquTypeCnt(gmo, gmoequ_C) || gmoGetEquTypeCnt(gmo, gmoequ_B) || gmoGetEquTypeCnt(gmo, gmoequ_X) )
{
gevLogStat(gev, "ERROR: Conic and logic constraints and external functions not supported by SCIP interface.\n");
gmoSolveStatSet(gmo, gmoSolveStat_Capability);
gmoModelStatSet(gmo, gmoModelStat_NoSolutionReturned);
return 1;
}
// set number of threads for linear algebra routines used in Ipopt
setNumThreads(gev, gevThreads(gev));
// update error printing callback in SCIP to use current gev
SCIPmessageSetErrorPrinting(printErrorGev, (void*)gev);
SCIP_RETCODE scipret;
// let GMO reader setup SCIP parameters and read options file
// do this here already so we know how to assemble dialog
scipret = SCIPreadParamsReaderGmo(scip);
if( scipret != SCIP_OKAY )
{
char buffer[256];
sprintf(buffer, "Error %d in call of SCIP function\n", scipret);
gevLogStatPChar(gev, buffer);
gmoSolveStatSet(gmo, gmoSolveStat_SystemErr);
gmoModelStatSet(gmo, gmoModelStat_ErrorNoSolution);
return 1;
}
SCIPinfoMessage(scip, NULL, "non-default parameter settings:\n");
SCIPwriteParams(scip, NULL, FALSE, TRUE);
char* interactive = NULL;
SCIP_CALL_ABORT( SCIPgetStringParam(scip, "gams/interactive", &interactive) );
assert(interactive != NULL);
#ifdef GAMS_BUILD
if( interactive[0] != '\0' && !palLicenseIsAcademic(pal) )
{
gevLogStat(gev, "SCIP interactive shell not available in demo mode.\n");
interactive[0] = '\0';
}
#endif
SCIP_Bool printstat;
SCIP_CALL_ABORT( SCIPgetBoolParam(scip, "display/statistics", &printstat) );
char* attrfile = NULL;
#if 0
SCIP_CALL( SCIPgetStringParam(scip, "constraints/attrfile", &attrfile) );
#endif
// setup commands to be executed by SCIP
SCIP_CALL_ABORT( SCIPaddDialogInputLine(scip, "readgams") ); // setup model
if( attrfile != NULL && *attrfile != '\0' )
{
char buffer[SCIP_MAXSTRLEN + 10];
size_t len;
len = strlen(attrfile);
if( len >= 3 && strcmp(&attrfile[len-3], ".ca") == 0 )
(void) SCIPsnprintf(buffer, sizeof(buffer), "read %g", attrfile);
else
(void) SCIPsnprintf(buffer, sizeof(buffer), "read %g ca", attrfile);
SCIP_CALL_ABORT( SCIPaddDialogInputLine(scip, buffer) ); // process constraints attribute file
}
if( interactive[0] == '\0' )
{
SCIP_CALL_ABORT( SCIPaddDialogInputLine(scip, "optimize") ); // solve model
if( printstat )
{
SCIP_CALL_ABORT( SCIPaddDialogInputLine(scip, "disp statistics") ); // display solution statistics
}
SCIP_CALL_ABORT( SCIPaddDialogInputLine(scip, "write gamssol") ); // pass solution to GMO
SCIP_CALL_ABORT( SCIPaddDialogInputLine(scip, "quit") ); // quit shell
}
else
{
// pass user commands to shell
SCIP_CALL_ABORT( SCIPaddDialogInputLine(scip, interactive) );
}
// run SCIP
scipret = SCIPstartInteraction(scip);
// evaluate SCIP return code
switch( scipret )
{
case SCIP_OKAY:
break;
case SCIP_READERROR:
/* if it's readerror, then we guess that it comes from encountering an unsupported gams instruction in the gmo readers makeExprtree method
* we still return with zero then
*/
gmoModelStatSet(gmo, gmoModelStat_NoSolutionReturned);
gmoSolveStatSet(gmo, gmoSolveStat_Capability);
break;
case SCIP_LPERROR:
case SCIP_MAXDEPTHLEVEL:
/* if SCIP failed due to internal error (forced LP solve failed, max depth level reached), also return zero */
gmoModelStatSet(gmo, gmoModelStat_ErrorNoSolution);
gmoSolveStatSet(gmo, gmoSolveStat_SolverErr);
break;
case SCIP_NOMEMORY:
/* there is no extra solver status for running out of memory, but memory is a resource, so return this */
gmoModelStatSet(gmo, gmoModelStat_ErrorNoSolution);
gmoSolveStatSet(gmo, gmoSolveStat_Resource);
break;
default:
{
char buffer[256];
sprintf(buffer, "Error %d in call of SCIP function\n", scipret);
gevLogStatPChar(gev, buffer);
gmoModelStatSet(gmo, gmoModelStat_ErrorNoSolution);
gmoSolveStatSet(gmo, gmoSolveStat_SystemErr);
return 1;
}
}
return 0;
}
/**
* @brief translates a SCIP_RETCODE into an error string
*
* @param[in] retcode SCIP_RETCODE you want to translate
* @param[out] buffer_str buffer to character array to store translated message, this must be at least of size \ref SCIP_MSG_MAX
* @return buffer_str or NULL, if retcode could not be translated
*/
inline char* SCIPgetErrorString(SCIP_RETCODE retcode, char* buffer_str, int buffersize)
{
// the following was copied from SCIPprintError
switch(retcode)
{
case SCIP_OKAY:
SCIPsnprintf(buffer_str, buffersize, "normal termination");
return buffer_str;
case SCIP_ERROR:
SCIPsnprintf(buffer_str, buffersize, "unspecified error");
return buffer_str;
case SCIP_NOMEMORY:
SCIPsnprintf(buffer_str, buffersize, "insufficient memory error");
return buffer_str;
case SCIP_READERROR:
SCIPsnprintf(buffer_str, buffersize, "file read error");
return buffer_str;
case SCIP_WRITEERROR:
SCIPsnprintf(buffer_str, buffersize, "file write error");
return buffer_str;
case SCIP_NOFILE:
SCIPsnprintf(buffer_str, buffersize, "file not found error");
return buffer_str;
case SCIP_FILECREATEERROR:
SCIPsnprintf(buffer_str, buffersize, "cannot create file");
return buffer_str;
case SCIP_LPERROR:
SCIPsnprintf(buffer_str, buffersize, "error in LP solver");
return buffer_str;
case SCIP_NOPROBLEM:
SCIPsnprintf(buffer_str, buffersize, "no problem exists");
return buffer_str;
case SCIP_INVALIDCALL:
SCIPsnprintf(buffer_str, buffersize, "method cannot be called at this time in solution process");
return buffer_str;
case SCIP_INVALIDDATA:
SCIPsnprintf(buffer_str, buffersize, "method cannot be called with this type of data");
return buffer_str;
case SCIP_INVALIDRESULT:
SCIPsnprintf(buffer_str, buffersize, "method returned an invalid result code");
return buffer_str;
case SCIP_PLUGINNOTFOUND:
SCIPsnprintf(buffer_str, buffersize, "a required plugin was not found");
return buffer_str;
case SCIP_PARAMETERUNKNOWN:
SCIPsnprintf(buffer_str, buffersize, "the parameter with the given name was not found");
return buffer_str;
case SCIP_PARAMETERWRONGTYPE:
SCIPsnprintf(buffer_str, buffersize, "the parameter is not of the expected type");
return buffer_str;
case SCIP_PARAMETERWRONGVAL:
SCIPsnprintf(buffer_str, buffersize, "the value is invalid for the given parameter");
return buffer_str;
case SCIP_KEYALREADYEXISTING:
SCIPsnprintf(buffer_str, buffersize, "the given key is already existing in table");
return buffer_str;
case SCIP_MAXDEPTHLEVEL:
SCIPsnprintf(buffer_str, buffersize, "maximal branching depth level exceeded");
return buffer_str;
default:
return NULL;
}
}
/** @brief constructs a SCIPEexception from an error code
*
* this constructs a new SCIPException from given error code
* @param[in] retcode SCIP error code
*/
SCIPException(SCIP_RETCODE retcode)
{
if(SCIPgetErrorString(retcode, _msg, SCIP_MSG_MAX)==NULL)
SCIPsnprintf(_msg, SCIP_MSG_MAX, "unknown SCIP retcode %d",retcode);
}
/** read fixed variable */
static
SCIP_RETCODE getFixedVariable(
SCIP* scip, /**< SCIP data structure */
CIPINPUT* cipinput /**< CIP parsing data */
)
{
SCIP_Bool success;
SCIP_VAR* var;
char* buf;
char* endptr;
char name[SCIP_MAXSTRLEN];
buf = cipinput->strbuf;
if( strncmp(buf, "CONSTRAINTS", 11) == 0 )
cipinput->section = CIP_CONSTRAINTS;
else if( strncmp(buf, "END", 3) == 0 )
cipinput->section = CIP_END;
if( cipinput->section != CIP_FIXEDVARS )
return SCIP_OKAY;
SCIPdebugMessage("parse fixed variable\n");
/* parse the variable */
SCIP_CALL( SCIPparseVar(scip, &var, buf, TRUE, FALSE, NULL, NULL, NULL, NULL, NULL, &endptr, &success) );
if( !success )
{
SCIPerrorMessage("syntax error in variable information (line: %d):\n%s\n", cipinput->linenumber, cipinput->strbuf);
cipinput->haserror = TRUE;
return SCIP_OKAY;
}
/* skip intermediate stuff */
buf = endptr;
while ( *buf != '\0' && (*buf == ' ' || *buf == ',') )
++buf;
/* check whether variable is fixed */
if ( strncmp(buf, "fixed:", 6) == 0 )
{
SCIP_CALL( SCIPaddVar(scip, var) );
SCIPdebug( SCIP_CALL( SCIPprintVar(scip, var, NULL) ) );
}
else if ( strncmp(buf, "negated:", 8) == 0 )
{
SCIP_CONS* lincons;
SCIP_VAR* negvar;
SCIP_Real vals[2];
SCIP_VAR* vars[2];
buf += 8;
/* we can just parse the next variable (ignoring all other information in between) */
SCIP_CALL( SCIPparseVarName(scip, buf, &negvar, &endptr) );
if ( negvar == NULL )
{
SCIPerrorMessage("could not parse negated variable (line: %d):\n%s\n", cipinput->linenumber, cipinput->strbuf);
cipinput->haserror = TRUE;
return SCIP_OKAY;
}
assert(SCIPvarIsBinary(var));
assert(SCIPvarIsBinary(negvar));
SCIP_CALL( SCIPaddVar(scip, var) );
SCIPdebugMessage("creating negated variable <%s> (of <%s>) ...\n", SCIPvarGetName(var), SCIPvarGetName(negvar) );
SCIPdebug( SCIP_CALL( SCIPprintVar(scip, var, NULL) ) );
/* add linear constraint for negation */
(void) SCIPsnprintf(name, SCIP_MAXSTRLEN, "neg_%s", SCIPvarGetName(var) );
vars[0] = var;
vars[1] = negvar;
vals[0] = 1.0;
vals[1] = 1.0;
SCIPdebugMessage("coupling constraint:\n");
SCIP_CALL( SCIPcreateConsLinear(scip, &lincons, name, 2, vars, vals, 1.0, 1.0, TRUE, TRUE, TRUE, TRUE, TRUE, FALSE, FALSE, FALSE, TRUE, FALSE) );
SCIPdebugPrintCons(scip, lincons, NULL);
SCIP_CALL( SCIPaddCons(scip, lincons) );
SCIP_CALL( SCIPreleaseCons(scip, &lincons) );
}
else if ( strncmp(buf, "aggregated:", 11) == 0 )
{
/* handle (multi-)aggregated variables */
SCIP_CONS* lincons;
SCIP_Real* vals;
SCIP_VAR** vars;
SCIP_Real rhs = 0.0;
const char* str;
int nvarssize = 20;
int requsize;
int nvars;
buf += 11;
SCIPdebugMessage("parsing aggregated variable <%s> ...\n", SCIPvarGetName(var));
/* first parse constant */
if ( ! SCIPstrToRealValue(buf, &rhs, &endptr) )
{
SCIPerrorMessage("expected constant when aggregated variable information (line: %d):\n%s\n", cipinput->linenumber, buf);
cipinput->haserror = TRUE;
return SCIP_OKAY;
}
/* check whether constant is 0.0 */
str = endptr;
while ( *str != '\0' && isspace(*str) )
++str;
/* if next char is '<' we found a variable -> constant is 0 */
if ( *str != '<' )
{
SCIPdebugMessage("constant: %f\n", rhs);
buf = endptr;
}
else
{
/* otherwise keep buf */
rhs = 0.0;
}
/* initialize buffers for storing the variables and values */
SCIP_CALL( SCIPallocBufferArray(scip, &vars, nvarssize) );
SCIP_CALL( SCIPallocBufferArray(scip, &vals, nvarssize) );
vars[0] = var;
vals[0] = -1.0;
--nvarssize;
/* parse linear sum to get variables and coefficients */
SCIP_CALL( SCIPparseVarsLinearsum(scip, buf, &(vars[1]), &(vals[1]), &nvars, nvarssize, &requsize, &endptr, &success) );
if ( success && requsize > nvarssize )
{
/* realloc buffers and try again */
nvarssize = requsize;
SCIP_CALL( SCIPreallocBufferArray(scip, &vars, nvarssize + 1) );
SCIP_CALL( SCIPreallocBufferArray(scip, &vals, nvarssize + 1) );
SCIP_CALL( SCIPparseVarsLinearsum(scip, buf, &(vars[1]), &(vals[1]), &nvars, nvarssize, &requsize, &endptr, &success) );
assert( ! success || requsize <= nvarssize); /* if successful, then should have had enough space now */
}
if( success )
{
/* add aggregated variable */
SCIP_CALL( SCIPaddVar(scip, var) );
/* special handling of variables that seem to be slack variables of indicator constraints */
str = SCIPvarGetName(var);
if ( strncmp(str, "indslack", 8) == 0 )
{
(void) strcpy(name, "indlin");
(void) strncat(name, str+8, SCIP_MAXSTRLEN-7);
}
else if ( strncmp(str, "t_indslack", 10) == 0 )
{
(void) strcpy(name, "indlin");
(void) strncat(name, str+10, SCIP_MAXSTRLEN-7);
}
else
(void) SCIPsnprintf(name, SCIP_MAXSTRLEN, "%s", SCIPvarGetName(var) );
/* add linear constraint for (multi-)aggregation */
SCIPdebugMessage("coupling constraint:\n");
SCIP_CALL( SCIPcreateConsLinear(scip, &lincons, name, nvars + 1, vars, vals, -rhs, -rhs, TRUE, TRUE, TRUE, TRUE, TRUE, FALSE, FALSE, FALSE, TRUE, FALSE) );
SCIPdebugPrintCons(scip, lincons, NULL);
SCIP_CALL( SCIPaddCons(scip, lincons) );
SCIP_CALL( SCIPreleaseCons(scip, &lincons) );
}
else
{
SCIPwarningMessage(scip, "Could not read (multi-)aggregated variable <%s>: dependent variables unkown - consider changing the order (line: %d):\n%s\n",
SCIPvarGetName(var), cipinput->linenumber, buf);
}
SCIPfreeBufferArray(scip, &vals);
SCIPfreeBufferArray(scip, &vars);
}
else
{
SCIPerrorMessage("unknown section when parsing variables (line: %d):\n%s\n", cipinput->linenumber, buf);
cipinput->haserror = TRUE;
return SCIP_OKAY;
}
SCIP_CALL( SCIPreleaseVar(scip, &var) );
return SCIP_OKAY;
}
/** creates a display column */
SCIP_RETCODE SCIPdispCreate(
SCIP_DISP** disp, /**< pointer to store display column */
SCIP_SET* set, /**< global SCIP settings */
SCIP_MESSAGEHDLR* messagehdlr, /**< message handler */
BMS_BLKMEM* blkmem, /**< block memory for parameter settings */
const char* name, /**< name of display column */
const char* desc, /**< description of display column */
const char* header, /**< head line of display column */
SCIP_DISPSTATUS dispstatus, /**< display activation status of display column */
SCIP_DECL_DISPCOPY ((*dispcopy)), /**< copy method of display column or NULL if you don't want to copy your plugin into sub-SCIPs */
SCIP_DECL_DISPFREE ((*dispfree)), /**< destructor of display column */
SCIP_DECL_DISPINIT ((*dispinit)), /**< initialize display column */
SCIP_DECL_DISPEXIT ((*dispexit)), /**< deinitialize display column */
SCIP_DECL_DISPINITSOL ((*dispinitsol)), /**< solving process initialization method of display column */
SCIP_DECL_DISPEXITSOL ((*dispexitsol)), /**< solving process deinitialization method of display column */
SCIP_DECL_DISPOUTPUT ((*dispoutput)), /**< output method */
SCIP_DISPDATA* dispdata, /**< display column data */
int width, /**< width of display column (no. of chars used) */
int priority, /**< priority of display column */
int position, /**< relative position of display column */
SCIP_Bool stripline /**< should the column be separated with a line from its right neighbor? */
)
{
char paramname[SCIP_MAXSTRLEN];
char paramdesc[SCIP_MAXSTRLEN];
assert(disp != NULL);
assert(name != NULL);
assert(desc != NULL);
assert(header != NULL);
assert(dispoutput != NULL);
assert(width >= 0);
SCIP_ALLOC( BMSallocMemory(disp) );
SCIP_ALLOC( BMSduplicateMemoryArray(&(*disp)->name, name, strlen(name)+1) );
SCIP_ALLOC( BMSduplicateMemoryArray(&(*disp)->desc, desc, strlen(desc)+1) );
SCIP_ALLOC( BMSduplicateMemoryArray(&(*disp)->header, header, strlen(header)+1) );
(*disp)->dispstatus = dispstatus;
(*disp)->dispcopy = dispcopy;
(*disp)->dispfree = dispfree;
(*disp)->dispinit = dispinit;
(*disp)->dispexit = dispexit;
(*disp)->dispinitsol = dispinitsol;
(*disp)->dispexitsol = dispexitsol;
(*disp)->dispoutput = dispoutput;
(*disp)->dispdata = dispdata;
(*disp)->width = width;
(*disp)->priority = priority;
(*disp)->position = position;
(*disp)->stripline = stripline;
(*disp)->initialized = FALSE;
(*disp)->active = (dispstatus == SCIP_DISPSTATUS_ON);
/* add parameters */
(void) SCIPsnprintf(paramname, SCIP_MAXSTRLEN, "display/%s/active", name);
(void) SCIPsnprintf(paramdesc, SCIP_MAXSTRLEN, "display activation status of display column <%s> (0: off, 1: auto, 2:on)", name);
SCIP_CALL( SCIPsetAddIntParam(set, messagehdlr, blkmem, paramname, paramdesc,
(int*)(&(*disp)->dispstatus), FALSE, (int)dispstatus, 0, 2, SCIPparamChgdDispActive, NULL) );
return SCIP_OKAY;
}
/** creates a presolver */
SCIP_RETCODE SCIPpresolCreate(
SCIP_PRESOL** presol, /**< pointer to store presolver */
SCIP_SET* set, /**< global SCIP settings */
SCIP_MESSAGEHDLR* messagehdlr, /**< message handler */
BMS_BLKMEM* blkmem, /**< block memory for parameter settings */
const char* name, /**< name of presolver */
const char* desc, /**< description of presolver */
int priority, /**< priority of the presolver (>= 0: before, < 0: after constraint handlers) */
int maxrounds, /**< maximal number of presolving rounds the presolver participates in (-1: no limit) */
SCIP_Bool delay, /**< should presolver be delayed, if other presolvers found reductions? */
SCIP_DECL_PRESOLCOPY ((*presolcopy)), /**< copy method of presolver or NULL if you don't want to copy your plugin into sub-SCIPs */
SCIP_DECL_PRESOLFREE ((*presolfree)), /**< destructor of presolver to free user data (called when SCIP is exiting) */
SCIP_DECL_PRESOLINIT ((*presolinit)), /**< initialization method of presolver (called after problem was transformed) */
SCIP_DECL_PRESOLEXIT ((*presolexit)), /**< deinitialization method of presolver (called before transformed problem is freed) */
SCIP_DECL_PRESOLINITPRE((*presolinitpre)),/**< presolving initialization method of presolver (called when presolving is about to begin) */
SCIP_DECL_PRESOLEXITPRE((*presolexitpre)),/**< presolving deinitialization method of presolver (called after presolving has been finished) */
SCIP_DECL_PRESOLEXEC ((*presolexec)), /**< execution method of presolver */
SCIP_PRESOLDATA* presoldata /**< presolver data */
)
{
char paramname[SCIP_MAXSTRLEN];
char paramdesc[SCIP_MAXSTRLEN];
assert(presol != NULL);
assert(name != NULL);
assert(desc != NULL);
SCIP_ALLOC( BMSallocMemory(presol) );
SCIP_ALLOC( BMSduplicateMemoryArray(&(*presol)->name, name, strlen(name)+1) );
SCIP_ALLOC( BMSduplicateMemoryArray(&(*presol)->desc, desc, strlen(desc)+1) );
(*presol)->presolcopy = presolcopy;
(*presol)->presolfree = presolfree;
(*presol)->presolinit = presolinit;
(*presol)->presolexit = presolexit;
(*presol)->presolinitpre = presolinitpre;
(*presol)->presolexitpre = presolexitpre;
(*presol)->presolexec = presolexec;
(*presol)->presoldata = presoldata;
SCIP_CALL( SCIPclockCreate(&(*presol)->setuptime, SCIP_CLOCKTYPE_DEFAULT) );
SCIP_CALL( SCIPclockCreate(&(*presol)->presolclock, SCIP_CLOCKTYPE_DEFAULT) );
(*presol)->wasdelayed = FALSE;
(*presol)->initialized = FALSE;
/* add parameters */
(void) SCIPsnprintf(paramname, SCIP_MAXSTRLEN, "presolving/%s/priority", name);
(void) SCIPsnprintf(paramdesc, SCIP_MAXSTRLEN, "priority of presolver <%s>", name);
SCIP_CALL( SCIPsetAddIntParam(set, messagehdlr, blkmem, paramname, paramdesc,
&(*presol)->priority, TRUE, priority, INT_MIN/4, INT_MAX/4,
paramChgdPresolPriority, (SCIP_PARAMDATA*)(*presol)) ); /*lint !e740*/
(void) SCIPsnprintf(paramname, SCIP_MAXSTRLEN, "presolving/%s/maxrounds", name);
SCIP_CALL( SCIPsetAddIntParam(set, messagehdlr, blkmem, paramname,
"maximal number of presolving rounds the presolver participates in (-1: no limit)",
&(*presol)->maxrounds, FALSE, maxrounds, -1, INT_MAX, NULL, NULL) ); /*lint !e740*/
(void) SCIPsnprintf(paramname, SCIP_MAXSTRLEN, "presolving/%s/delay", name);
SCIP_CALL( SCIPsetAddBoolParam(set, messagehdlr, blkmem, paramname,
"should presolver be delayed, if other presolvers found reductions?",
&(*presol)->delay, TRUE, delay, NULL, NULL) ); /*lint !e740*/
return SCIP_OKAY;
}
/** presolving execution method */
static
SCIP_DECL_PRESOLEXEC(presolExecInttobinary)
{ /*lint --e{715}*/
SCIP_VAR** scipvars;
SCIP_VAR** vars;
int nbinvars;
int nintvars;
int v;
assert(result != NULL);
*result = SCIP_DIDNOTRUN;
if( SCIPdoNotAggr(scip) )
return SCIP_OKAY;
/* get the problem variables */
scipvars = SCIPgetVars(scip);
nbinvars = SCIPgetNBinVars(scip);
nintvars = SCIPgetNIntVars(scip);
if( nintvars == 0 )
return SCIP_OKAY;
*result = SCIP_DIDNOTFIND;
/* copy the integer variables into an own array, since adding binary variables affects the left-most slots in the
* array and thereby interferes with our search loop
*/
SCIP_CALL( SCIPduplicateBufferArray(scip, &vars, &scipvars[nbinvars], nintvars) );
/* scan the integer variables for possible conversion into binaries;
* we have to collect the variables first in an own
*/
for( v = 0; v < nintvars; ++v )
{
SCIP_Real lb;
SCIP_Real ub;
assert(SCIPvarGetType(vars[v]) == SCIP_VARTYPE_INTEGER);
/* get variable's bounds */
lb = SCIPvarGetLbGlobal(vars[v]);
ub = SCIPvarGetUbGlobal(vars[v]);
/* check if bounds are exactly one apart */
if( SCIPisEQ(scip, lb, ub - 1.0) )
{
SCIP_VAR* binvar;
char binvarname[SCIP_MAXSTRLEN];
SCIP_Bool infeasible;
SCIP_Bool redundant;
SCIP_Bool aggregated;
SCIPdebugMessage("converting <%s>[%g,%g] into binary variable\n", SCIPvarGetName(vars[v]), lb, ub);
/* create binary variable */
(void) SCIPsnprintf(binvarname, SCIP_MAXSTRLEN, "%s_bin", SCIPvarGetName(vars[v]));
SCIP_CALL( SCIPcreateVar(scip, &binvar, binvarname, 0.0, 1.0, 0.0, SCIP_VARTYPE_BINARY,
SCIPvarIsInitial(vars[v]), SCIPvarIsRemovable(vars[v]), NULL, NULL, NULL, NULL, NULL) );
SCIP_CALL( SCIPaddVar(scip, binvar) );
/* aggregate integer and binary variable */
SCIP_CALL( SCIPaggregateVars(scip, vars[v], binvar, 1.0, -1.0, lb, &infeasible, &redundant, &aggregated) );
/* release binary variable */
SCIP_CALL( SCIPreleaseVar(scip, &binvar) );
/* it can be the case that this aggregation detects an infeasibility; for example, during the copy of the
* variable bounds from the integer variable to the binary variable, infeasibility can be detected; this can
* happen because an upper bound or a lower bound of such a variable bound variable was "just" changed and the
* varbound constraint handler, who would detect that infeasibility (since it was creating it from a varbound
* constraint), was called before that bound change was detected due to the presolving priorities;
*/
if( infeasible )
{
*result = SCIP_CUTOFF;
break;
}
assert(redundant);
assert(aggregated);
(*nchgvartypes)++;
*result = SCIP_SUCCESS;
}
}
/* free temporary memory */
SCIPfreeBufferArray(scip, &vars);
return SCIP_OKAY;
}
/* standard "main" method for mex interface */
void mexFunction(
int nlhs, /* number of expected outputs */
mxArray* plhs[], /* array of pointers to output arguments */
int nrhs, /* number of inputs */
const mxArray* prhs[] /* array of pointers to input arguments */
)
{
SCIP* scip;
SCIP_VAR** vars;
SCIP_Real* objs;
SCIP_Real* lhss;
SCIP_Real* rhss;
SCIP_Real* lbs;
SCIP_Real* ubs;
SCIP_Real* matrix;
SCIP_Real* bestsol;
SCIP_Real* objval;
char* vartypes;
char objsense[SCIP_MAXSTRLEN];
int nvars;
int nconss;
int stringsize;
int i;
if( SCIPmajorVersion() < 2 )
{
mexErrMsgTxt("SCIP versions less than 2.0 are not supported\n");
return;
}
/* initialize SCIP */
SCIP_CALL_ABORT( SCIPcreate(&scip) );
/* output SCIP information */
SCIPprintVersion(scip, NULL);
/* include default SCIP plugins */
SCIP_CALL_ABORT( SCIPincludeDefaultPlugins(scip) );
if( nlhs != 2 || nrhs != 8 )
mexErrMsgTxt("invalid number of parameters. Call as [bestsol, objval] = matscip(matrix, lhs, rhs, obj, lb, ub, vartype, objsense)\n");
if( mxIsSparse(prhs[0]) )
mexErrMsgTxt("sparse matrices are not supported yet"); /* ???????? of course this has to change */
/* get linear constraint coefficient matrix */
matrix = mxGetPr(prhs[0]);
if( matrix == NULL )
mexErrMsgTxt("matrix must not be NULL");
if( mxGetNumberOfDimensions(prhs[0]) != 2 )
mexErrMsgTxt("matrix must have exactly two dimensions");
/* get dimensions of matrix */
nconss = mxGetM(prhs[0]);
nvars = mxGetN(prhs[0]);
assert(nconss > 0);
assert(nvars > 0);
/* get left hand sides of linear constraints */
lhss = mxGetPr(prhs[1]);
if( mxGetM(prhs[1]) != nconss )
mexErrMsgTxt("dimension of left hand side vector does not match matrix dimension");
assert(lhss != NULL);
/* get right hand sides of linear constraints */
rhss = mxGetPr(prhs[2]);
if( mxGetM(prhs[2]) != nconss )
mexErrMsgTxt("dimension of right hand side vector does not match matrix dimension");
assert(rhss != NULL);
/* get objective coefficients */
objs = mxGetPr(prhs[3]);
if( mxGetM(prhs[3]) != nvars )
mexErrMsgTxt("dimension of objective coefficient vector does not match matrix dimension");
/* get lower bounds of variables */
lbs = mxGetPr(prhs[4]);
if( mxGetM(prhs[4]) != nvars )
mexErrMsgTxt("dimension of lower bound vector does not match matrix dimension");
/* get upper bounds of variables */
ubs = mxGetPr(prhs[5]);
if( mxGetM(prhs[5]) != nvars )
mexErrMsgTxt("dimension of upper bound vector does not match matrix dimension");
/* allocate memory for variable type characters */
SCIP_CALL_ABORT( SCIPallocMemoryArray(scip, &vartypes, nvars+1) );
/* get variable types */
if( mxGetString(prhs[6], vartypes, nvars+1) != 0 )
mexErrMsgTxt("Error when parsing variable types, maybe a wrong vector dimension?");
/* get objective sense */
stringsize = mxGetNumberOfElements(prhs[7]);
if( stringsize != 3 )
mexErrMsgTxt("objective sense must be a three character word: \"max\" or \"min\"");
if( mxGetString(prhs[7], objsense, stringsize+1) != 0)
mexErrMsgTxt("Error when parsing objective sense string");
if( strcmp(objsense,"max") != 0 && strcmp(objsense,"min") != 0 )
mexErrMsgTxt("objective sense must be either \"max\" or \"min\"");
/* get output parameters */
plhs[0] = mxCreateDoubleMatrix(nvars, 1, mxREAL);
bestsol = mxGetPr(plhs[0]);
plhs[1] = mxCreateDoubleScalar(mxREAL);
objval = mxGetPr(plhs[1]);
/* create SCIP problem */
SCIP_CALL_ABORT( SCIPcreateProb(scip, "mex_prob", NULL, NULL, NULL, NULL, NULL, NULL, NULL) );
/* allocate memory for variable array */
SCIP_CALL_ABORT( SCIPallocMemoryArray(scip, &vars, nvars) );
/* create variables */
for( i = 0; i < nvars; ++i)
{
SCIP_VARTYPE vartype;
char varname[SCIP_MAXSTRLEN];
/* convert vartype character to SCIP vartype */
if( vartypes[i] == 'i' )
vartype = SCIP_VARTYPE_INTEGER;
else if( vartypes[i] == 'b' )
vartype = SCIP_VARTYPE_BINARY;
else if( vartypes[i] == 'c' )
vartype = SCIP_VARTYPE_CONTINUOUS;
else
mexErrMsgTxt("unkown variable type");
/* variables get canonic names x_i */
(void) SCIPsnprintf(varname, SCIP_MAXSTRLEN, "x_%d", i);
/* create variable object and add it to SCIP */
SCIP_CALL_ABORT( SCIPcreateVar(scip, &vars[i], varname, lbs[i], ubs[i], objs[i],
vartype, TRUE, FALSE, NULL, NULL, NULL, NULL, NULL) );
assert(vars[i] != NULL);
SCIP_CALL_ABORT( SCIPaddVar(scip, vars[i]) );
}
/* create linear constraints */
for( i = 0; i < nconss; ++i )
{
SCIP_CONS* cons;
char consname[SCIP_MAXSTRLEN];
int j;
/* constraints get canonic names cons_i */
(void) SCIPsnprintf(consname, SCIP_MAXSTRLEN, "cons_%d", i);
/* create empty linear constraint */
SCIP_CALL_ABORT( SCIPcreateConsLinear(scip, &cons, consname, 0, NULL, NULL, lhss[i], rhss[i],
TRUE, TRUE, TRUE, TRUE, TRUE, FALSE, FALSE, FALSE, FALSE, FALSE) );
/* add non-zero coefficients to linear constraint */
for( j = 0; j < nvars; ++j )
{
if( !SCIPisFeasZero(scip, matrix[i+j*nconss]) )
{
SCIP_CALL_ABORT( SCIPaddCoefLinear(scip, cons, vars[j], matrix[i+j*nconss]) );
}
}
/* add constraint to SCIP and release it */
SCIP_CALL_ABORT( SCIPaddCons(scip, cons) );
SCIP_CALL_ABORT( SCIPreleaseCons(scip, &cons) );
}
/* set objective sense in SCIP */
if( strcmp(objsense,"max") == 0)
{
SCIP_CALL_ABORT( SCIPsetObjsense(scip, SCIP_OBJSENSE_MAXIMIZE) );
}
else if( strcmp(objsense,"min") == 0)
{
SCIP_CALL_ABORT( SCIPsetObjsense(scip, SCIP_OBJSENSE_MINIMIZE) );
}
else
/* this should have been caught earlier when parsing objsense */
mexErrMsgTxt("unkown objective sense");
/* solve SCIP problem */
SCIP_CALL_ABORT( SCIPsolve(scip) );
/* if SCIP found a solution, pass it back into MATLAB output parameters */
if( SCIPgetNSols > 0 )
{
SCIP_SOL* scipbestsol;
/* get incumbent solution vector */
scipbestsol = SCIPgetBestSol(scip);
assert(scipbestsol != NULL);
/* get objective value of incumbent solution */
*objval = SCIPgetSolOrigObj(scip, scipbestsol);
assert(!SCIPisInfinity(scip, REALABS(*objval)));
/* copy solution values into output vector */
for( i = 0; i < nvars; ++i )
bestsol[i] = SCIPgetSolVal(scip,scipbestsol,vars[i]);
}
/* release variables */
for( i = 0; i < nvars; ++i )
{
SCIP_CALL_ABORT( SCIPreleaseVar(scip, &vars[i]) );
}
/* free memory for variable arrays */
SCIPfreeMemoryArray(scip, &vartypes);
SCIPfreeMemoryArray(scip, &vars);
/* deinitialize SCIP */
SCIP_CALL_ABORT( SCIPfree(&scip) );
/* check for memory leaks */
BMScheckEmptyMemory();
return;
}
/** writes problem data to file with given reader or returns SCIP_DIDNOTRUN */
SCIP_RETCODE SCIPreaderWrite(
SCIP_READER* reader, /**< reader */
SCIP_PROB* prob, /**< problem data */
SCIP_SET* set, /**< global SCIP settings */
FILE* file, /**< output file (or NULL for standard output) */
const char* extension, /**< file format */
SCIP_Bool genericnames, /**< using generic variable and constraint names? */
SCIP_RESULT* result /**< pointer to store the result of the callback method */
)
{
SCIP_RETCODE retcode;
assert(reader != NULL);
assert(set != NULL);
assert(extension != NULL);
assert(result != NULL);
/* check, if reader is applicable on the given file */
if( readerIsApplicable(reader, extension) && reader->readerwrite != NULL )
{
SCIP_VAR** vars;
int nvars;
SCIP_VAR** fixedvars;
int nfixedvars;
SCIP_CONS** conss;
int nconss;
int i;
SCIP_CONS* cons;
char* name;
const char* consname;
const char** varnames;
const char** fixedvarnames;
const char** consnames;
varnames = NULL;
fixedvarnames = NULL;
consnames = NULL;
vars = prob->vars;
nvars = prob->nvars;
fixedvars = prob->fixedvars;
nfixedvars = prob->nfixedvars;
/* case of the transformed problem, we want to write currently valid problem */
if( prob->transformed )
{
SCIP_CONSHDLR** conshdlrs;
int nconshdlrs;
conshdlrs = set->conshdlrs;
nconshdlrs = set->nconshdlrs;
/* collect number of constraints which have to be enforced; these are the constraints which currency (locally)
* enabled; these also includes the local constraints
*/
nconss = 0;
for( i = 0; i < nconshdlrs; ++i )
{
/* check if all constraints of the constraint handler should be written */
if( set->write_allconss )
nconss += SCIPconshdlrGetNConss(conshdlrs[i]);
else
nconss += SCIPconshdlrGetNEnfoConss(conshdlrs[i]);
}
SCIPdebugMessage("Writing %d constraints.\n", nconss);
SCIP_ALLOC( BMSallocMemoryArray(&conss, nconss) );
/* copy the constraints */
nconss = 0;
for( i = 0; i < nconshdlrs; ++i )
{
SCIP_CONS** conshdlrconss;
int nconshdlrconss;
int c;
/* check if all constraints of the constraint handler should be written */
if( set->write_allconss )
{
conshdlrconss = SCIPconshdlrGetConss(conshdlrs[i]);
nconshdlrconss = SCIPconshdlrGetNConss(conshdlrs[i]);
}
else
{
conshdlrconss = SCIPconshdlrGetEnfoConss(conshdlrs[i]);
nconshdlrconss = SCIPconshdlrGetNEnfoConss(conshdlrs[i]);
}
SCIPdebugMessage("Conshdlr <%s> has %d constraints to write from all in all %d constraints.\n", SCIPconshdlrGetName(conshdlrs[i]), nconshdlrconss, SCIPconshdlrGetNConss(conshdlrs[i]));
for( c = 0; c < nconshdlrconss; ++c )
{
conss[nconss] = conshdlrconss[c];
nconss++;
}
}
}
else
{
conss = prob->conss;
nconss = prob->nconss;
}
if( genericnames )
{
SCIP_VAR* var;
int size;
/* save variable and constraint names and replace these names by generic names */
/* allocate memory for saving the original variable and constraint names */
SCIP_ALLOC( BMSallocMemoryArray(&varnames, nvars) );
SCIP_ALLOC( BMSallocMemoryArray(&fixedvarnames, nfixedvars) );
SCIP_ALLOC( BMSallocMemoryArray(&consnames, nconss) );
/* compute length of the generic variable names:
* - nvars + 1 to avoid log of zero
* - +3 (zero at end + 'x' + 1 because we round down)
* Example: 10 -> need 4 chars ("x10\0")
*/
size = (int) log10(nvars+1.0) + 3;
for( i = 0; i < nvars; ++i )
{
var = vars[i];
varnames[i] = SCIPvarGetName(var);
SCIP_ALLOC( BMSallocMemoryArray(&name, size) );
(void) SCIPsnprintf(name, size, "x%d", i + set->write_genoffset);
SCIPvarSetNamePointer(var, name);
}
/* compute length of the generic variable names */
size = (int) log10(nfixedvars+1.0) + 3;
for( i = 0; i < nfixedvars; ++i )
{
var = fixedvars[i];
fixedvarnames[i] = SCIPvarGetName(var);
SCIP_ALLOC( BMSallocMemoryArray(&name, size) );
(void) SCIPsnprintf(name, size, "y%d", i);
SCIPvarSetNamePointer(var, name);
}
/* compute length of the generic constraint names */
size = (int) log10(nconss+1.0) + 3;
for( i = 0; i < nconss; ++i )
{
cons = conss[i];
consnames[i] = SCIPconsGetName(cons);
SCIP_ALLOC( BMSallocMemoryArray(&name, size) );
(void) SCIPsnprintf(name, size, "c%d", i);
SCIPconsSetNamePointer(cons, name);
}
}
/* call reader to write problem */
retcode = reader->readerwrite(set->scip, reader, file, prob->name, prob->probdata, prob->transformed,
prob->transformed ? SCIP_OBJSENSE_MINIMIZE : prob->objsense, prob->objscale, prob->objoffset,
vars, nvars, prob->nbinvars, prob->nintvars, prob->nimplvars, prob->ncontvars,
fixedvars, nfixedvars, prob->startnvars,
conss, nconss, prob->maxnconss, prob->startnconss, genericnames, result);
/* reset variable and constraint names to original names */
if( genericnames )
{
assert(varnames != NULL);
assert(fixedvarnames != NULL);
assert(consnames != NULL);
for( i = 0; i < nvars; ++i )
resetVarname(vars[i], varnames[i]);
for( i = 0; i < nfixedvars; ++i )
resetVarname(fixedvars[i], fixedvarnames[i]);
for( i = 0; i < nconss; ++i )
{
cons = conss[i];
/* get pointer to temporary generic name and free the memory */
consname = SCIPconsGetName(cons);
BMSfreeMemory(&consname);
/* reset name */
SCIPconsSetNamePointer(cons, consnames[i]);
}
/* free memory */
BMSfreeMemoryArray(&varnames);
BMSfreeMemoryArray(&fixedvarnames);
BMSfreeMemoryArray(&consnames);
}
if( prob->transformed )
{
/* free memory */
BMSfreeMemoryArray(&conss);
}
}
else
{
*result = SCIP_DIDNOTRUN;
retcode = SCIP_OKAY;
}
/* check for reader errors */
if( retcode == SCIP_WRITEERROR )
return retcode;
SCIP_CALL( retcode );
return SCIP_OKAY;
}
/** reduced cost pricing method of variable pricer for feasible LPs */
static
SCIP_DECL_PRICERREDCOST(pricerRedcostBinpacking)
{ /*lint --e{715}*/
SCIP* subscip;
SCIP_PRICERDATA* pricerdata;
SCIP_CONS** conss;
SCIP_VAR** vars;
int* ids;
SCIP_Bool addvar;
SCIP_SOL** sols;
int nsols;
int s;
int nitems;
SCIP_Longint capacity;
SCIP_Real timelimit;
SCIP_Real memorylimit;
assert(scip != NULL);
assert(pricer != NULL);
(*result) = SCIP_DIDNOTRUN;
/* get the pricer data */
pricerdata = SCIPpricerGetData(pricer);
assert(pricerdata != NULL);
capacity = pricerdata->capacity;
conss = pricerdata->conss;
ids = pricerdata->ids;
nitems = pricerdata->nitems;
/* get the remaining time and memory limit */
SCIP_CALL( SCIPgetRealParam(scip, "limits/time", &timelimit) );
if( !SCIPisInfinity(scip, timelimit) )
timelimit -= SCIPgetSolvingTime(scip);
SCIP_CALL( SCIPgetRealParam(scip, "limits/memory", &memorylimit) );
if( !SCIPisInfinity(scip, memorylimit) )
memorylimit -= SCIPgetMemUsed(scip)/1048576.0;
/* initialize SCIP */
SCIP_CALL( SCIPcreate(&subscip) );
SCIP_CALL( SCIPincludeDefaultPlugins(subscip) );
/* create problem in sub SCIP */
SCIP_CALL( SCIPcreateProbBasic(subscip, "pricing") );
SCIP_CALL( SCIPsetObjsense(subscip, SCIP_OBJSENSE_MAXIMIZE) );
/* do not abort subproblem on CTRL-C */
SCIP_CALL( SCIPsetBoolParam(subscip, "misc/catchctrlc", FALSE) );
/* disable output to console */
SCIP_CALL( SCIPsetIntParam(subscip, "display/verblevel", 0) );
/* set time and memory limit */
SCIP_CALL( SCIPsetRealParam(subscip, "limits/time", timelimit) );
SCIP_CALL( SCIPsetRealParam(subscip, "limits/memory", memorylimit) );
SCIP_CALL( SCIPallocMemoryArray(subscip, &vars, nitems) );
/* initialization local pricing problem */
SCIP_CALL( initPricing(scip, pricerdata, subscip, vars) );
SCIPdebugMessage("solve pricer problem\n");
/* solve sub SCIP */
SCIP_CALL( SCIPsolve(subscip) );
sols = SCIPgetSols(subscip);
nsols = SCIPgetNSols(subscip);
addvar = FALSE;
/* loop over all solutions and create the corresponding column to master if the reduced cost are negative for master,
* that is the objective value i greater than 1.0
*/
for( s = 0; s < nsols; ++s )
{
SCIP_Bool feasible;
SCIP_SOL* sol;
/* the soultion should be sorted w.r.t. the objective function value */
assert(s == 0 || SCIPisFeasGE(subscip, SCIPgetSolOrigObj(subscip, sols[s-1]), SCIPgetSolOrigObj(subscip, sols[s])));
sol = sols[s];
assert(sol != NULL);
/* check if solution is feasible in original sub SCIP */
SCIP_CALL( SCIPcheckSolOrig(subscip, sol, &feasible, FALSE, FALSE ) );
if( !feasible )
{
SCIPwarningMessage(scip, "solution in pricing problem (capacity <%d>) is infeasible\n", capacity);
continue;
}
/* check if the solution has a value greater than 1.0 */
if( SCIPisFeasGT(subscip, SCIPgetSolOrigObj(subscip, sol), 1.0) )
{
SCIP_VAR* var;
SCIP_VARDATA* vardata;
int* consids;
char strtmp[SCIP_MAXSTRLEN];
char name[SCIP_MAXSTRLEN];
int nconss;
int o;
int v;
SCIPdebug( SCIP_CALL( SCIPprintSol(subscip, sol, NULL, FALSE) ) );
nconss = 0;
(void) SCIPsnprintf(name, SCIP_MAXSTRLEN, "items");
SCIP_CALL( SCIPallocBufferArray(scip, &consids, nitems) );
/* check which variables are fixed -> which item belongs to this packing */
for( o = 0, v = 0; o < nitems; ++o )
{
if( !SCIPconsIsEnabled(conss[o]) )
continue;
assert(SCIPgetNFixedonesSetppc(scip, conss[o]) == 0);
if( SCIPgetSolVal(subscip, sol, vars[v]) > 0.5 )
{
(void) SCIPsnprintf(strtmp, SCIP_MAXSTRLEN, "_%d", ids[o]);
strcat(name, strtmp);
consids[nconss] = o;
nconss++;
}
else
assert( SCIPisFeasEQ(subscip, SCIPgetSolVal(subscip, sol, vars[v]), 0.0) );
v++;
}
SCIP_CALL( SCIPvardataCreateBinpacking(scip, &vardata, consids, nconss) );
/* create variable for a new column with objective function coefficient 0.0 */
SCIP_CALL( SCIPcreateVarBinpacking(scip, &var, name, 1.0, FALSE, TRUE, vardata) );
/* add the new variable to the pricer store */
SCIP_CALL( SCIPaddPricedVar(scip, var, 1.0) );
addvar = TRUE;
/* change the upper bound of the binary variable to lazy since the upper bound is already enforced due to
* the objective function the set covering constraint; The reason for doing is that, is to avoid the bound
* of x <= 1 in the LP relaxation since this bound constraint would produce a dual variable which might have
* a positive reduced cost
*/
SCIP_CALL( SCIPchgVarUbLazy(scip, var, 1.0) );
/* check which variable are fixed -> which orders belong to this packing */
for( v = 0; v < nconss; ++v )
{
assert(SCIPconsIsEnabled(conss[consids[v]]));
SCIP_CALL( SCIPaddCoefSetppc(scip, conss[consids[v]], var) );
}
SCIPdebug(SCIPprintVar(scip, var, NULL) );
SCIP_CALL( SCIPreleaseVar(scip, &var) );
SCIPfreeBufferArray(scip, &consids);
}
else
break;
}
/* free pricer MIP */
SCIPfreeMemoryArray(subscip, &vars);
if( addvar || SCIPgetStatus(subscip) == SCIP_STATUS_OPTIMAL )
(*result) = SCIP_SUCCESS;
/* free sub SCIP */
SCIP_CALL( SCIPfree(&subscip) );
return SCIP_OKAY;
}
