/** creates a new solution for the original problem by copying the solution of the subproblem */ static SCIP_RETCODE createNewSol( SCIP* scip, /**< original SCIP data structure */ SCIP_HEUR* heur, /**< the current heuristic */ SCIP_SOL* sol, /**< solution of the subproblem */ SCIP_Bool* success /**< used to store whether new solution was found or not */ ) { SCIP_VAR** vars; /* the original problem's variables */ int nvars; /* the original problem's number of variables */ SCIP_Real* solvals; /* solution values of the subproblem */ SCIP_SOL* newsol; /* solution to be created for the original problem */ assert(scip != NULL); /* get variables' data */ SCIP_CALL( SCIPgetVarsData(scip, &vars, &nvars, NULL, NULL, NULL, NULL) ); SCIP_CALL( SCIPallocBufferArray(scip, &solvals, nvars) ); /* copy the solution */ SCIP_CALL( SCIPgetSolVals(scip, sol, nvars, vars, solvals) ); /* create new solution for the original problem */ SCIP_CALL( SCIPcreateSol(scip, &newsol, heur) ); SCIP_CALL( SCIPsetSolVals(scip, newsol, nvars, vars, solvals) ); /* try to add new solution to scip and free it immediately */ SCIP_CALL( SCIPtrySolFree(scip, &newsol, FALSE, TRUE, TRUE, TRUE, success) ); SCIPfreeBufferArray(scip, &solvals); return SCIP_OKAY; }
/** creates a new solution for the original problem by copying the solution of the subproblem */ static SCIP_RETCODE createNewSol( SCIP* scip, /**< original SCIP data structure */ SCIP* subscip, /**< SCIP structure of the subproblem */ SCIP_VAR** subvars, /**< the variables of the subproblem */ SCIP_HEUR* heur, /**< crossover heuristic structure */ SCIP_SOL* subsol, /**< solution of the subproblem */ int* solindex, /**< index of the solution */ SCIP_Bool* success /**< used to store whether new solution was found or not */ ) { SCIP_VAR** vars; /* the original problem's variables */ int nvars; SCIP_SOL* newsol; /* solution to be created for the original problem */ SCIP_Real* subsolvals; /* solution values of the subproblem */ assert(scip != NULL); assert(subscip != NULL); assert(subvars != NULL); assert(subsol != NULL); /* get variables' data */ SCIP_CALL( SCIPgetVarsData(scip, &vars, &nvars, NULL, NULL, NULL, NULL) ); /* sub-SCIP may have more variables than the number of active (transformed) variables in the main SCIP * since constraint copying may have required the copy of variables that are fixed in the main SCIP */ assert(nvars <= SCIPgetNOrigVars(subscip)); SCIP_CALL( SCIPallocBufferArray(scip, &subsolvals, nvars) ); /* copy the solution */ SCIP_CALL( SCIPgetSolVals(subscip, subsol, nvars, subvars, subsolvals) ); /* create new solution for the original problem */ SCIP_CALL( SCIPcreateSol(scip, &newsol, heur) ); SCIP_CALL( SCIPsetSolVals(scip, newsol, nvars, vars, subsolvals) ); *solindex = SCIPsolGetIndex(newsol); /* try to add new solution to scip and free it immediately */ SCIP_CALL( SCIPtrySolFree(scip, &newsol, FALSE, TRUE, TRUE, TRUE, success) ); SCIPfreeBufferArray(scip, &subsolvals); return SCIP_OKAY; }
/** creates a new solution for the original problem by copying the solution of the subproblem */ static SCIP_RETCODE createNewSol( SCIP* scip, /**< SCIP data structure of the original problem */ SCIP* subscip, /**< SCIP data structure of the subproblem */ SCIP_VAR** subvars, /**< the variables of the subproblem */ SCIP_HEUR* heur, /**< the Localbranching heuristic */ SCIP_SOL* subsol, /**< solution of the subproblem */ SCIP_Bool* success /**< pointer to store, whether new solution was found */ ) { SCIP_VAR** vars; int nvars; SCIP_SOL* newsol; SCIP_Real* subsolvals; assert( scip != NULL ); assert( subscip != NULL ); assert( subvars != NULL ); assert( subsol != NULL ); /* copy the solution */ SCIP_CALL( SCIPgetVarsData(scip, &vars, &nvars, NULL, NULL, NULL, NULL) ); /* sub-SCIP may have more variables than the number of active (transformed) variables in the main SCIP * since constraint copying may have required the copy of variables that are fixed in the main SCIP */ assert(nvars <= SCIPgetNOrigVars(subscip)); SCIP_CALL( SCIPallocBufferArray(scip, &subsolvals, nvars) ); /* copy the solution */ SCIP_CALL( SCIPgetSolVals(subscip, subsol, nvars, subvars, subsolvals) ); /* create new solution for the original problem */ SCIP_CALL( SCIPcreateSol(scip, &newsol, heur) ); SCIP_CALL( SCIPsetSolVals(scip, newsol, nvars, vars, subsolvals) ); SCIP_CALL( SCIPtrySolFree(scip, &newsol, FALSE, TRUE, TRUE, TRUE, success) ); SCIPfreeBufferArray(scip, &subsolvals); return SCIP_OKAY; }
/** execution method of primal heuristic */ static SCIP_DECL_HEUREXEC(heurExecOneopt) { /*lint --e{715}*/ SCIP_HEURDATA* heurdata; SCIP_SOL* bestsol; /* incumbent solution */ SCIP_SOL* worksol; /* heuristic's working solution */ SCIP_VAR** vars; /* SCIP variables */ SCIP_VAR** shiftcands; /* shiftable variables */ SCIP_ROW** lprows; /* SCIP LP rows */ SCIP_Real* activities; /* row activities for working solution */ SCIP_Real* shiftvals; SCIP_Real lb; SCIP_Real ub; SCIP_Bool localrows; SCIP_Bool valid; int nchgbound; int nbinvars; int nintvars; int nvars; int nlprows; int i; int nshiftcands; int shiftcandssize; 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; /* we only want to process each solution once */ bestsol = SCIPgetBestSol(scip); if( bestsol == NULL || heurdata->lastsolindex == SCIPsolGetIndex(bestsol) ) return SCIP_OKAY; /* reset the timing mask to its default value (at the root node it could be different) */ if( SCIPgetNNodes(scip) > 1 ) SCIPheurSetTimingmask(heur, HEUR_TIMING); /* get problem variables */ SCIP_CALL( SCIPgetVarsData(scip, &vars, &nvars, &nbinvars, &nintvars, NULL, NULL) ); nintvars += nbinvars; /* do not run if there are no discrete variables */ if( nintvars == 0 ) { *result = SCIP_DIDNOTRUN; return SCIP_OKAY; } if( heurtiming == SCIP_HEURTIMING_BEFOREPRESOL ) { SCIP* subscip; /* the subproblem created by zeroobj */ SCIP_HASHMAP* varmapfw; /* mapping of SCIP variables to sub-SCIP variables */ SCIP_VAR** subvars; /* subproblem's variables */ SCIP_Real* subsolvals; /* solution values of the subproblem */ SCIP_Real timelimit; /* time limit for zeroobj subproblem */ SCIP_Real memorylimit; /* memory limit for zeroobj subproblem */ SCIP_SOL* startsol; SCIP_SOL** subsols; int nsubsols; if( !heurdata->beforepresol ) return SCIP_OKAY; /* 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) ); /* 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 ) return SCIP_OKAY; /* 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) ); /* copy complete SCIP instance */ valid = FALSE; SCIP_CALL( SCIPcopy(scip, subscip, varmapfw, NULL, "oneopt", TRUE, FALSE, TRUE, &valid) ); SCIP_CALL( SCIPtransformProb(subscip) ); /* get variable image */ for( i = 0; i < nvars; i++ ) subvars[i] = (SCIP_VAR*) SCIPhashmapGetImage(varmapfw, vars[i]); /* copy the solution */ SCIP_CALL( SCIPallocBufferArray(scip, &subsolvals, nvars) ); SCIP_CALL( SCIPgetSolVals(scip, bestsol, nvars, vars, subsolvals) ); /* create start solution for the subproblem */ SCIP_CALL( SCIPcreateOrigSol(subscip, &startsol, NULL) ); SCIP_CALL( SCIPsetSolVals(subscip, startsol, nvars, subvars, subsolvals) ); /* try to add new solution to sub-SCIP and free it immediately */ valid = FALSE; SCIP_CALL( SCIPtrySolFree(subscip, &startsol, FALSE, FALSE, FALSE, FALSE, &valid) ); SCIPfreeBufferArray(scip, &subsolvals); SCIPhashmapFree(&varmapfw); /* disable statistic timing inside sub SCIP */ SCIP_CALL( SCIPsetBoolParam(subscip, "timing/statistictiming", FALSE) ); /* deactivate basically everything except oneopt in the sub-SCIP */ SCIP_CALL( SCIPsetPresolving(subscip, SCIP_PARAMSETTING_OFF, TRUE) ); SCIP_CALL( SCIPsetHeuristics(subscip, SCIP_PARAMSETTING_OFF, TRUE) ); SCIP_CALL( SCIPsetSeparating(subscip, SCIP_PARAMSETTING_OFF, TRUE) ); SCIP_CALL( SCIPsetLongintParam(subscip, "limits/nodes", 1LL) ); SCIP_CALL( SCIPsetRealParam(subscip, "limits/time", timelimit) ); SCIP_CALL( SCIPsetRealParam(subscip, "limits/memory", memorylimit) ); SCIP_CALL( SCIPsetBoolParam(subscip, "misc/catchctrlc", FALSE) ); SCIP_CALL( SCIPsetIntParam(subscip, "display/verblevel", 0) ); /* if necessary, some of the parameters have to be unfixed first */ if( SCIPisParamFixed(subscip, "lp/solvefreq") ) { SCIPwarningMessage(scip, "unfixing parameter lp/solvefreq in subscip of oneopt heuristic\n"); SCIP_CALL( SCIPunfixParam(subscip, "lp/solvefreq") ); } SCIP_CALL( SCIPsetIntParam(subscip, "lp/solvefreq", -1) ); if( SCIPisParamFixed(subscip, "heuristics/oneopt/freq") ) { SCIPwarningMessage(scip, "unfixing parameter heuristics/oneopt/freq in subscip of oneopt heuristic\n"); SCIP_CALL( SCIPunfixParam(subscip, "heuristics/oneopt/freq") ); } SCIP_CALL( SCIPsetIntParam(subscip, "heuristics/oneopt/freq", 1) ); if( SCIPisParamFixed(subscip, "heuristics/oneopt/forcelpconstruction") ) { SCIPwarningMessage(scip, "unfixing parameter heuristics/oneopt/forcelpconstruction in subscip of oneopt heuristic\n"); SCIP_CALL( SCIPunfixParam(subscip, "heuristics/oneopt/forcelpconstruction") ); } SCIP_CALL( SCIPsetBoolParam(subscip, "heuristics/oneopt/forcelpconstruction", TRUE) ); /* avoid recursive call, which would lead to an endless loop */ if( SCIPisParamFixed(subscip, "heuristics/oneopt/beforepresol") ) { SCIPwarningMessage(scip, "unfixing parameter heuristics/oneopt/beforepresol in subscip of oneopt heuristic\n"); SCIP_CALL( SCIPunfixParam(subscip, "heuristics/oneopt/beforepresol") ); } SCIP_CALL( SCIPsetBoolParam(subscip, "heuristics/oneopt/beforepresol", FALSE) ); if( valid ) { 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 zeroobj heuristic; sub-SCIP terminated with code <%d>\n",retcode); } #ifdef SCIP_DEBUG SCIP_CALL( SCIPprintStatistics(subscip, NULL) ); #endif } /* 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); valid = FALSE; for( i = 0; i < nsubsols && !valid; ++i ) { SCIP_CALL( createNewSol(scip, subscip, subvars, heur, subsols[i], &valid) ); if( valid ) *result = SCIP_FOUNDSOL; } /* free subproblem */ SCIPfreeBufferArray(scip, &subvars); SCIP_CALL( SCIPfree(&subscip) ); return SCIP_OKAY; } /* we can only work on solutions valid in the transformed space */ if( SCIPsolIsOriginal(bestsol) ) return SCIP_OKAY; if( heurtiming == SCIP_HEURTIMING_BEFORENODE && (SCIPhasCurrentNodeLP(scip) || heurdata->forcelpconstruction) ) { SCIP_Bool cutoff; cutoff = FALSE; SCIP_CALL( SCIPconstructLP(scip, &cutoff) ); SCIP_CALL( SCIPflushLP(scip) ); /* get problem variables again, SCIPconstructLP() might have added new variables */ SCIP_CALL( SCIPgetVarsData(scip, &vars, &nvars, &nbinvars, &nintvars, NULL, NULL) ); nintvars += nbinvars; } /* we need an LP */ if( SCIPgetNLPRows(scip) == 0 ) return SCIP_OKAY; *result = SCIP_DIDNOTFIND; nchgbound = 0; /* initialize data */ nshiftcands = 0; shiftcandssize = 8; heurdata->lastsolindex = SCIPsolGetIndex(bestsol); SCIP_CALL( SCIPcreateSolCopy(scip, &worksol, bestsol) ); SCIPsolSetHeur(worksol,heur); SCIPdebugMessage("Starting bound adjustment in 1-opt heuristic\n"); /* maybe change solution values due to global bound changes first */ for( i = nvars - 1; i >= 0; --i ) { SCIP_VAR* var; SCIP_Real solval; var = vars[i]; lb = SCIPvarGetLbGlobal(var); ub = SCIPvarGetUbGlobal(var); solval = SCIPgetSolVal(scip, bestsol,var); /* old solution value is smaller than the actual lower bound */ if( SCIPisFeasLT(scip, solval, lb) ) { /* set the solution value to the global lower bound */ SCIP_CALL( SCIPsetSolVal(scip, worksol, var, lb) ); ++nchgbound; SCIPdebugMessage("var <%s> type %d, old solval %g now fixed to lb %g\n", SCIPvarGetName(var), SCIPvarGetType(var), solval, lb); } /* old solution value is greater than the actual upper bound */ else if( SCIPisFeasGT(scip, solval, SCIPvarGetUbGlobal(var)) ) { /* set the solution value to the global upper bound */ SCIP_CALL( SCIPsetSolVal(scip, worksol, var, ub) ); ++nchgbound; SCIPdebugMessage("var <%s> type %d, old solval %g now fixed to ub %g\n", SCIPvarGetName(var), SCIPvarGetType(var), solval, ub); } } SCIPdebugMessage("number of bound changes (due to global bounds) = %d\n", nchgbound); SCIP_CALL( SCIPgetLPRowsData(scip, &lprows, &nlprows) ); SCIP_CALL( SCIPallocBufferArray(scip, &activities, nlprows) ); localrows = FALSE; valid = TRUE; /* initialize activities */ for( i = 0; i < nlprows; ++i ) { SCIP_ROW* row; row = lprows[i]; assert(SCIProwGetLPPos(row) == i); if( !SCIProwIsLocal(row) ) { activities[i] = SCIPgetRowSolActivity(scip, row, worksol); SCIPdebugMessage("Row <%s> has activity %g\n", SCIProwGetName(row), activities[i]); if( SCIPisFeasLT(scip, activities[i], SCIProwGetLhs(row)) || SCIPisFeasGT(scip, activities[i], SCIProwGetRhs(row)) ) { valid = FALSE; SCIPdebug( SCIP_CALL( SCIPprintRow(scip, row, NULL) ) ); SCIPdebugMessage("row <%s> activity %g violates bounds, lhs = %g, rhs = %g\n", SCIProwGetName(row), activities[i], SCIProwGetLhs(row), SCIProwGetRhs(row)); break; } } else localrows = TRUE; } if( !valid ) { /** @todo try to correct lp rows */ SCIPdebugMessage("Some global bound changes were not valid in lp rows.\n"); goto TERMINATE; } SCIP_CALL( SCIPallocBufferArray(scip, &shiftcands, shiftcandssize) ); SCIP_CALL( SCIPallocBufferArray(scip, &shiftvals, shiftcandssize) ); SCIPdebugMessage("Starting 1-opt heuristic\n"); /* enumerate all integer variables and find out which of them are shiftable */ for( i = 0; i < nintvars; i++ ) { if( SCIPvarGetStatus(vars[i]) == SCIP_VARSTATUS_COLUMN ) { SCIP_Real shiftval; SCIP_Real solval; /* find out whether the variable can be shifted */ solval = SCIPgetSolVal(scip, worksol, vars[i]); shiftval = calcShiftVal(scip, vars[i], solval, activities); /* insert the variable into the list of shifting candidates */ if( !SCIPisFeasZero(scip, shiftval) ) { SCIPdebugMessage(" -> Variable <%s> can be shifted by <%1.1f> \n", SCIPvarGetName(vars[i]), shiftval); if( nshiftcands == shiftcandssize) { shiftcandssize *= 8; SCIP_CALL( SCIPreallocBufferArray(scip, &shiftcands, shiftcandssize) ); SCIP_CALL( SCIPreallocBufferArray(scip, &shiftvals, shiftcandssize) ); } shiftcands[nshiftcands] = vars[i]; shiftvals[nshiftcands] = shiftval; nshiftcands++; } } } /* if at least one variable can be shifted, shift variables sorted by their objective */ if( nshiftcands > 0 ) { SCIP_Real shiftval; SCIP_Real solval; SCIP_VAR* var; /* the case that exactly one variable can be shifted is slightly easier */ if( nshiftcands == 1 ) { var = shiftcands[0]; assert(var != NULL); solval = SCIPgetSolVal(scip, worksol, var); shiftval = shiftvals[0]; assert(!SCIPisFeasZero(scip,shiftval)); SCIPdebugMessage(" Only one shiftcand found, var <%s>, which is now shifted by<%1.1f> \n", SCIPvarGetName(var), shiftval); SCIP_CALL( SCIPsetSolVal(scip, worksol, var, solval+shiftval) ); } else { SCIP_Real* objcoeffs; SCIP_CALL( SCIPallocBufferArray(scip, &objcoeffs, nshiftcands) ); SCIPdebugMessage(" %d shiftcands found \n", nshiftcands); /* sort the variables by their objective, optionally weighted with the shiftval */ if( heurdata->weightedobj ) { for( i = 0; i < nshiftcands; ++i ) objcoeffs[i] = SCIPvarGetObj(shiftcands[i])*shiftvals[i]; } else { for( i = 0; i < nshiftcands; ++i ) objcoeffs[i] = SCIPvarGetObj(shiftcands[i]); } /* sort arrays with respect to the first one */ SCIPsortRealPtr(objcoeffs, (void**)shiftcands, nshiftcands); /* try to shift each variable -> Activities have to be updated */ for( i = 0; i < nshiftcands; ++i ) { var = shiftcands[i]; assert(var != NULL); solval = SCIPgetSolVal(scip, worksol, var); shiftval = calcShiftVal(scip, var, solval, activities); SCIPdebugMessage(" -> Variable <%s> is now shifted by <%1.1f> \n", SCIPvarGetName(vars[i]), shiftval); assert(i > 0 || !SCIPisFeasZero(scip, shiftval)); assert(SCIPisFeasGE(scip, solval+shiftval, SCIPvarGetLbGlobal(var)) && SCIPisFeasLE(scip, solval+shiftval, SCIPvarGetUbGlobal(var))); SCIP_CALL( SCIPsetSolVal(scip, worksol, var, solval+shiftval) ); SCIP_CALL( updateRowActivities(scip, activities, var, shiftval) ); } SCIPfreeBufferArray(scip, &objcoeffs); } /* if the problem is a pure IP, try to install the solution, if it is a MIP, solve LP again to set the continuous * variables to the best possible value */ if( nvars == nintvars || !SCIPhasCurrentNodeLP(scip) || SCIPgetLPSolstat(scip) != SCIP_LPSOLSTAT_OPTIMAL ) { SCIP_Bool success; /* since we ignore local rows, we cannot guarantee their feasibility and have to set the checklprows flag to * TRUE if local rows are present */ SCIP_CALL( SCIPtrySol(scip, worksol, FALSE, FALSE, FALSE, localrows, &success) ); if( success ) { SCIPdebugMessage("found feasible shifted solution:\n"); SCIPdebug( SCIP_CALL( SCIPprintSol(scip, worksol, NULL, FALSE) ) ); heurdata->lastsolindex = SCIPsolGetIndex(bestsol); *result = SCIP_FOUNDSOL; } } else { SCIP_Bool lperror; #ifdef NDEBUG SCIP_RETCODE retstat; #endif SCIPdebugMessage("shifted solution should be feasible -> solve LP to fix continuous variables to best values\n"); /* start diving to calculate the LP relaxation */ SCIP_CALL( SCIPstartDive(scip) ); /* set the bounds of the variables: fixed for integers, global bounds for continuous */ for( i = 0; i < nvars; ++i ) { if( SCIPvarGetStatus(vars[i]) == SCIP_VARSTATUS_COLUMN ) { SCIP_CALL( SCIPchgVarLbDive(scip, vars[i], SCIPvarGetLbGlobal(vars[i])) ); SCIP_CALL( SCIPchgVarUbDive(scip, vars[i], SCIPvarGetUbGlobal(vars[i])) ); } } /* apply this after global bounds to not cause an error with intermediate empty domains */ for( i = 0; i < nintvars; ++i ) { if( SCIPvarGetStatus(vars[i]) == SCIP_VARSTATUS_COLUMN ) { solval = SCIPgetSolVal(scip, worksol, vars[i]); SCIP_CALL( SCIPchgVarLbDive(scip, vars[i], solval) ); SCIP_CALL( SCIPchgVarUbDive(scip, vars[i], solval) ); } } /* solve LP */ SCIPdebugMessage(" -> old LP iterations: %" SCIP_LONGINT_FORMAT "\n", SCIPgetNLPIterations(scip)); /**@todo in case of an MINLP, if SCIPisNLPConstructed() is TRUE, say, rather solve the NLP instead of the LP */ /* Errors in the LP solver should not kill the overall solving process, if the LP is just needed for a heuristic. * Hence in optimized mode, the return code is caught and a warning is printed, only in debug mode, SCIP will stop. */ #ifdef NDEBUG retstat = SCIPsolveDiveLP(scip, -1, &lperror, NULL); if( retstat != SCIP_OKAY ) { SCIPwarningMessage(scip, "Error while solving LP in Oneopt heuristic; LP solve terminated with code <%d>\n",retstat); } #else SCIP_CALL( SCIPsolveDiveLP(scip, -1, &lperror, NULL) ); #endif SCIPdebugMessage(" -> new LP iterations: %" SCIP_LONGINT_FORMAT "\n", SCIPgetNLPIterations(scip)); SCIPdebugMessage(" -> error=%u, status=%d\n", lperror, SCIPgetLPSolstat(scip)); /* check if this is a feasible solution */ if( !lperror && SCIPgetLPSolstat(scip) == SCIP_LPSOLSTAT_OPTIMAL ) { SCIP_Bool success; /* copy the current LP solution to the working solution */ SCIP_CALL( SCIPlinkLPSol(scip, worksol) ); SCIP_CALL( SCIPtrySol(scip, worksol, FALSE, FALSE, FALSE, FALSE, &success) ); /* check solution for feasibility */ if( success ) { SCIPdebugMessage("found feasible shifted solution:\n"); SCIPdebug( SCIP_CALL( SCIPprintSol(scip, worksol, NULL, FALSE) ) ); heurdata->lastsolindex = SCIPsolGetIndex(bestsol); *result = SCIP_FOUNDSOL; } } /* terminate the diving */ SCIP_CALL( SCIPendDive(scip) ); } } SCIPdebugMessage("Finished 1-opt heuristic\n"); SCIPfreeBufferArray(scip, &shiftvals); SCIPfreeBufferArray(scip, &shiftcands); TERMINATE: SCIPfreeBufferArray(scip, &activities); SCIP_CALL( SCIPfreeSol(scip, &worksol) ); return SCIP_OKAY; }
/** execution method of primal heuristic */ static SCIP_DECL_HEUREXEC(heurExecForward) { /*lint --e{715}*/ SCIP_PROBDATA* probdata; int n; int p; int ndep; /* "_" means the matrix for blas */ SCIP_Real* y; /* [n] */ SCIP_Real* orig_X_; /* [n*p] */ SCIP_Real* orig_Q_; /* [p*p] <- (X^t) X */ SCIP_Real* orig_q; /* [p] <- (X^t) y */ SCIP_Real r; int* Mdep; /* [ndep] */ int* groupX; /* [ndep*p] */ /* for forward selection */ int dim; int* list; /* [p] */ SCIP_Real* a; /* [dim] */ SCIP_Real* a_old; /* [dim-1] */ SCIP_Real* a_new; /* [dim] */ SCIP_Real RSS; /* residual sum of square */ SCIP_Real RSS_new; SCIP_Real AIC; SCIP_Real AIC_new; int ublb; int *Branchz; /* [3*p] */ /* * X: sub matrix of orig_X_ * Y: (X^t X)^-1 * X_new = (X, x_i); * Z: (X_new ^t X_new)^-1 * = ( V v v^t u ) */ SCIP_Real* Xy; /* sub vector of orig_q */ SCIP_Real* X_; SCIP_Real* Y_; /* [(dim-1)*(dim-1)] */ SCIP_Real* Z_; /* [dim*dim] */ SCIP_Real* W_; /* [dim*dim] */ SCIP_Real* V_; /* [(dim-1)*(dim-1)] */ SCIP_Real* v; /* [dim-1] */ SCIP_Real u; SCIP_Real* b; /* [dim-1] */ SCIP_Real* c; /* [dim-1] */ SCIP_Real* d; /* [n] */ /* variables */ SCIP_VAR** var_a; /* [p] continuous variables */ SCIP_VAR** var_z; /* [p] 01 variables */ SCIP_VAR** var_ep; /* [n] continuous variables */ SCIP_VAR* var_rss; /* continuous variable, residual sum of squares */ SCIP_VAR* var_log; /* continuous variable, log(rss) */ /* set solution */ SCIP_Real *ep; int nsols; int store; SCIP_SOL** sols; SCIP_Real objval; SCIP_SOL* sol; SCIP_Real* solvals; SCIP_Bool success; int nvars = SCIPgetNVars(scip); SCIP_VAR** vars; int i,j,t,ct; int memo; assert(heur != NULL); assert(scip != NULL); assert(strcmp(SCIPheurGetName(heur), HEUR_NAME) == 0); assert(result != NULL); #if MYPARA_LOG printf("forward selection!\n"); #endif /* get heuristic data */ /* SCIP_HEURDATA* heurdata; heurdata = SCIPheurGetData(heur); assert(heurdata != NULL); assert(lastsolindices != NULL); */ /* get values from probdata */ probdata = SCIPgetProbData(scip); assert(probdata != NULL); n = SCIPprobdataGetNdatas(probdata); p = SCIPprobdataGetNexvars(probdata); ndep = SCIPprobdataGetNdep(probdata); y = SCIPprobdataGety(probdata); orig_X_ = SCIPprobdataGetX(probdata); orig_Q_ = SCIPprobdataGetQ(probdata); orig_q = SCIPprobdataGetq(probdata); r = SCIPprobdataGetr(probdata); if( ndep ){ Mdep = SCIPprobdataGetMdep(probdata); groupX = SCIPprobdataGetgroupX(probdata); }else{ Mdep = NULL; groupX = NULL; } /* variables */ var_a = SCIPprobdataGetVars_a(probdata); var_z = SCIPprobdataGetVars_z(probdata); var_ep = SCIPprobdataGetVars_ep(probdata); var_rss = SCIPprobdataGetVar_rss(probdata); var_log = SCIPprobdataGetVar_log(probdata); /* get branching info */ /* alloc */ SCIP_CALL( SCIPallocBufferArray(scip, &Branchz, 3*p)); GenerateZeroVecInt( 3*p, Branchz); for(i=0; i<p; ++i){ ublb = SCIPround(scip, SCIPcomputeVarUbLocal(scip, var_z[i]) + SCIPcomputeVarLbLocal(scip, var_z[i])); *(Branchz+(ublb*p)+i) = 1; } #if MYPARA_LOG for(i=0; i<3; i++){ for(j=0; j<p; j++){ printf("%d, ", *(Branchz+(i*p)+j)); } newline(); } #endif if( ndep ){ for(i=0; i<ndep; i++){ memo = -1; for(j=0; j<p; j++){ if( *(groupX+(i*p)+j)==1 ){ if( *(Branchz+j)==1 ) break; if( *(Branchz+p+j)==1 ) memo=j; if( j==Mdep[i] ){ if( memo==-1 ){ printf("error in heur_backward.c\n"); stop(); } *(Branchz+p+memo) = 0; *(Branchz+memo) = 1; break; } } } } } #if MYPARA_LOG printf("linear dependent\n"); if( ndep ){ for(i=0; i<3; i++){ for(j=0; j<p; j++){ printf("%d, ", *(Branchz+(i*p)+j)); } newline(); } } #endif /* alloc */ SCIP_CALL( SCIPallocBufferArray(scip, &X_, n*p)); SCIP_CALL( SCIPallocBufferArray(scip, &Xy, p)); SCIP_CALL( SCIPallocBufferArray(scip, &d, n)); SCIP_CALL( SCIPallocBufferArray(scip, &list, p)); /* initialize from Branchz */ #if MYPARA_LOG printf("initialization\n"); #endif GenerateZeroVecInt( p, list); dim = 0; memo = -1; AIC = 1e+06; SCIP_CALL( SCIPallocBufferArray(scip, &a_old, dim+1)); for(i=0; i<p; i++){ if( Branchz[i]==1 ){ /* if z_i is fixed to 0 */ list[i] = -1; }else if( Branchz[p+i]==1 ){ /* if z_i is unfixed */ list[i] = 0; }else if( Branchz[2*p+i]==1 ){ /* if z_i is fixed 1 */ dim++; list[i] = dim; if( dim == 1 ){ a_old[0] = orig_q[i] / mat_( orig_Q_, p, i, i); RSS = RSSvalue( 1, a_old, &orig_q[i], r); AIC = AICvalue( n, dim, RSS); /* update X_ and Xy */ mydcopy_( &orig_X_[n * i], &X_[n * (dim-1)], n); Xy[dim-1] = orig_q[i]; /* generate Y ( dim = 1 ) */ SCIP_CALL( SCIPallocBufferArray( scip, &Y_, dim*dim)); Y_[0] = 1 / mat_( orig_Q_, p, i, i); }else{ /* alloc */ SCIPfreeBufferArray(scip, &a_old); SCIP_CALL( SCIPallocBufferArray( scip, &a_old, dim)); SCIP_CALL( SCIPallocBufferArray( scip, &b, dim-1)); SCIP_CALL( SCIPallocBufferArray( scip, &c, dim-1)); SCIP_CALL( SCIPallocBufferArray( scip, &v, dim-1)); SCIP_CALL( SCIPallocBufferArray( scip, &V_, (dim-1)*(dim-1))); SCIP_CALL( SCIPallocBufferArray( scip, &Z_, (dim)*(dim))); /* 1. b <- X^t x_i */ dgemv_t( X_, n, dim-1, &orig_X_[n * i], b); //printv( dim-1, b); /* 2. c <- Y b */ dgemv_2( Y_, dim-1, dim-1, b, c); //printv( dim-1, c); /* 3. d <- - X c + x_i */ dgemv_1( X_, n, dim-1, c, &orig_X_[n * i], -1.0, 1.0, d); //printv( n, d); /* 4. u <- 1/<x_i, d> */ u = 1.0 / myddot_( &orig_X_[n * i], d, n); //prints(u); /* 5. v <- - u c */ mydscal_( c, dim-1, -u, v); //printv( dim-1, v); /* 6. V <- Y + u c c^t */ dger_1( Y_, c, c, dim-1, dim-1, u, V_); //printM_( V_, dim-1, dim-1); /* 7. Z */ /* V */ for(j=0; j<(dim-1); j++){ for(t=0; t<(dim-1); t++){ *(Z_ + j + (t*dim) ) = mat_( V_, dim-1, j, t); } } /* v */ for(j=0; j<(dim-1); j++){ *(Z_ + dim-1 + (j*dim) ) = v[j]; *(Z_ + j + ((dim-1)*dim)) = v[j]; } /* u */ *(Z_ + dim-1 + ((dim-1)*dim)) = u; //printM_( Z_, dim, dim); /* 8. a_old <- Z (Xy) */ Xy[dim-1] = orig_q[i]; dgemv_2( Z_, dim, dim, Xy, a_old); //printv( dim, a_old); RSS = RSSvalue( dim, a_old, Xy, r); AIC = AICvalue( n, dim, RSS); /* copy */ SCIPfreeBufferArray(scip, &Y_); SCIP_CALL( SCIPallocBufferArray(scip, &Y_, dim*dim)); mydcopy_( Z_, Y_, dim*dim); /* update X_ and Xy */ mydcopy_( &orig_X_[n * i], &X_[n * (dim-1)], n); Xy[dim-1] = orig_q[i]; /* free */ SCIPfreeBufferArray(scip, &b); SCIPfreeBufferArray(scip, &c); SCIPfreeBufferArray(scip, &v); SCIPfreeBufferArray(scip, &V_); SCIPfreeBufferArray(scip, &Z_); } #if MYPARA_LOG printf("---> %dth variable, AIC:%f\n", i, AIC); #endif }else{ printf("error:heur_forward.c\n"); stop(); } } if( dim == 0 ){ #if MYPARA_LOG printf("[dim:0]\n"); #endif dim++; RSS = 1e+06; for(i=0; i<p; i++){ if( list[i] == 0 ){ a_old[0] = orig_q[i] / mat_( orig_Q_, p, i, i); RSS_new = RSSvalue( 1, a_old, &orig_q[i], r); if( RSS_new < RSS ){ RSS = RSS_new; memo = i; } #if MYPARA_LOG printf("%d: RSS = %f\n", i, RSS_new); #endif } } if( memo < 0 || memo >= p ){ printf("error in heur_forward.c\n"); stop(); } AIC = AICvalue( n, dim, RSS); list[memo] = dim; /* update X_ and Xy */ mydcopy_( &orig_X_[n * memo], &X_[n * (dim-1)], n); Xy[dim-1] = orig_q[memo]; /* generate Y ( dim = 1 ) */ SCIP_CALL( SCIPallocBufferArray( scip, &Y_, dim*dim)); Y_[0] = 1 / mat_( orig_Q_, p, memo, memo); #if MYPARA_LOG printf("---> %dth variable, AIC:%f\n", memo, AIC); #endif } /* if ( dim==0 ) */ while(1){ dim++; memo = -1; RSS = 1e+06; #if MYPARA_LOG printf("(dim=%d) ", dim); Longline(); #endif /* alloc */ SCIP_CALL( SCIPallocBufferArray( scip, &a_new, dim)); SCIP_CALL( SCIPallocBufferArray( scip, &a, dim)); SCIP_CALL( SCIPallocBufferArray( scip, &b, dim-1)); SCIP_CALL( SCIPallocBufferArray( scip, &c, dim-1)); SCIP_CALL( SCIPallocBufferArray( scip, &v, dim-1)); SCIP_CALL( SCIPallocBufferArray( scip, &V_, (dim-1)*(dim-1))); SCIP_CALL( SCIPallocBufferArray( scip, &Z_, (dim)*(dim))); SCIP_CALL( SCIPallocBufferArray( scip, &W_, (dim)*(dim))); for(i=0; i<p; i++){ /* * 1. b <- X^t x_i * 2. c <- Y b * 3. d <- - X c + x_i * 4. u <- 1 / <x_i, d> * 5. v <- - u c * 6. V <- Y + u c c^t * 7. Z <- ( V v v^t u ) * 8. a_new <- Z (Xy) */ if( list[i]==0 ){ /* 1. b <- X^t x_i */ dgemv_t( X_, n, dim-1, &orig_X_[n * i], b); //printv( dim-1, b); /* 2. c <- Y b */ dgemv_2( Y_, dim-1, dim-1, b, c); //printv( dim-1, c); /* 3. d <- - X c + x_i */ dgemv_1( X_, n, dim-1, c, &orig_X_[n * i], -1.0, 1.0, d); //printv( n, d); /* 4. u <- 1/<x_i, d> */ u = 1.0 / myddot_( &orig_X_[n * i], d, n); //prints(u); /* 5. v <- - u c */ mydscal_( c, dim-1, -u, v); //printv( dim-1, v); /* 6. V <- Y + u c c^t */ dger_1( Y_, c, c, dim-1, dim-1, u, V_); //printM_( V_, dim-1, dim-1); /* 7. Z */ /* V */ for(j=0; j<(dim-1); j++){ for(t=0; t<(dim-1); t++){ *(Z_ + j + (t*dim) ) = mat_( V_, dim-1, j, t); } } /* v */ for(j=0; j<(dim-1); j++){ *(Z_ + dim-1 + (j*dim) ) = v[j]; *(Z_ + j + ((dim-1)*dim)) = v[j]; } /* u */ *(Z_ + dim-1 + ((dim-1)*dim)) = u; //printM_( Z_, dim, dim); /* 8. a_new <- Z (Xy) */ Xy[dim-1] = orig_q[i]; dgemv_2( Z_, dim, dim, Xy, a_new); //printv( dim, a_new); /* test */ RSS_new = RSSvalue( dim, a_new, Xy, r); if( RSS_new < RSS ){ RSS = RSS_new; memo = i; mydcopy_( Z_, W_, dim*dim); mydcopy_( a_new, a, dim); } #if MYPARA_LOG printf("%d: RSS = %f\n", i, RSS_new); #endif } } if( memo < 0 || memo >= p ){ if( memo == -1 ){ for(i=0; i<p; i++){ if( list[i] == 0 ){ memo = i; break; } } if( memo != -1 ){ printf("error in heur_forward.c\n"); stop(); } }else{ printf("error in heur_forward.c\n"); stop(); } } AIC_new = AICvalue( n, dim, RSS); if( AIC_new < AIC ){ AIC = AIC_new; list[memo] = dim; #if MYPARA_LOG printf("---> %dth variable, AIC:%f\n", memo, AIC); #endif /* copy and free */ SCIPfreeBufferArray(scip, &Y_); SCIP_CALL( SCIPallocBufferArray(scip, &Y_, dim*dim)); mydcopy_( W_, Y_, dim*dim); SCIPfreeBufferArray(scip, &a_old); SCIP_CALL( SCIPallocBufferArray(scip, &a_old, dim)); mydcopy_( a, a_old, dim); /* update X_ and Xy */ mydcopy_( &orig_X_[n * memo], &X_[n * (dim-1)], n); Xy[dim-1] = orig_q[memo]; }else{ memo = -1; SCIPfreeBufferArray(scip, Y_); #if MYPARA_LOG printf("--> no selection, (AIC:%f)\n", AIC_new); #endif } /* free */ SCIPfreeBufferArray(scip, &a_new); SCIPfreeBufferArray(scip, &a); SCIPfreeBufferArray(scip, &b); SCIPfreeBufferArray(scip, &c); SCIPfreeBufferArray(scip, &v); SCIPfreeBufferArray(scip, &V_); SCIPfreeBufferArray(scip, &Z_); SCIPfreeBufferArray(scip, &W_); if( memo == -1 ){ dim--; break; } } nsols = SCIPgetNSols(scip); if( nsols < MP_NUM_SOL ){ store = 1; }else{ sols = SCIPgetSols(scip); objval = AIC; nsols = MP_NUM_SOL; if( objval < SCIPgetSolOrigObj(scip,sols[nsols-1]) ){ store = 1; }else{ store = 0; } } if( store ){ /* generate solution */ /* alloc */ SCIP_CALL( SCIPallocBufferArray(scip, &ep, n)); dgemv_1( X_, n, dim, a_old, y, -1.0, 1.0, ep); /* set solution */ /* alloc */ SCIP_CALL( SCIPallocBufferArray(scip, &solvals, nvars)); SCIP_CALL( SCIPallocBufferArray(scip, &vars, nvars)); ct=0; /* a */ for(i=0; i<p; ++i){ vars[ct] = var_a[i]; if( list[i] > 0 ){ solvals[ct] = a_old[list[i]-1]; }else{ solvals[ct] = 0.0; } ct++; } /* z */ for(i=0; i<p; i++){ vars[ct] = var_z[i]; if( list[i] > 0 ){ solvals[ct] = 1.0; }else{ solvals[ct] = 0.0; } ct++; } /* ep */ for(i=0; i<n; ++i){ vars[ct] = var_ep[i]; solvals[ct] = ep[i]; ct++; } vars[ct] = var_rss; solvals[ct] = myddot_( ep, ep, n); ct++; vars[ct] = var_log; solvals[ct] = log(myddot_( ep, ep, n)); ct++; if( ct!=nvars ){ SCIPerrorMessage("It is unexpected error in set sol,"); printf("( ct, nvars) = ( %d, %d)", ct, nvars); stop(); } SCIP_CALL( SCIPcreateSol(scip, &sol, heur)); SCIP_CALL( SCIPsetSolVals(scip, sol, nvars, vars, solvals)); SCIP_CALL( SCIPtrySolFree(scip, &sol, TRUE, FALSE, TRUE, TRUE, &success)); /* free */ SCIPfreeBufferArray(scip, &ep); SCIPfreeBufferArray(scip, &solvals); SCIPfreeBufferArray(scip, &vars); } /* free */ SCIPfreeBufferArray(scip, &d); SCIPfreeBufferArray(scip, &X_); SCIPfreeBufferArray(scip, &Xy); SCIPfreeBufferArray(scip, &a_old); SCIPfreeBufferArray(scip, &list); SCIPfreeBufferArray(scip, &Branchz); *result = SCIP_FOUNDSOL; return SCIP_OKAY; }