RsBundle  Diff

Differences From Artifact [7bfe7b8320]:

  • File src/solver.rs — part of check-in [80086db562] at 2019-07-15 10:33:45 on branch trunk — solver: fix initialization of `Solver` in `solve_iter` (user: fifr size: 37077)

To Artifact [802624df74]:

  • File src/solver.rs — part of check-in [bf831bc6e2] at 2019-07-15 12:20:08 on branch trunk — Solver: simplify re-raise of master problem errors (user: fifr size: 36492)

92
93
94
95
96
97
98






99
100
101
102
103
104
105
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111







+
+
+
+
+
+







}

impl<E> From<ParameterError> for SolverError<E> {
    fn from(err: ParameterError) -> SolverError<E> {
        SolverError::Parameter(err)
    }
}

impl<E> From<MasterProblemError> for SolverError<E> {
    fn from(err: MasterProblemError) -> SolverError<E> {
        SolverError::Master(err)
    }
}

/**
 * The current state of the bundle method.
 *
 * Captures the current state of the bundle method during the run of
 * the algorithm. This state is passed to certain callbacks like
 * Terminator or Weighter so that they can compute their result
501
502
503
504
505
506
507
508

509
510
511
512
513
514
515
516
517
507
508
509
510
511
512
513

514


515
516
517
518
519
520
521







-
+
-
-







            nxt_mods: dvec![],
            new_cutval: 0.0,
            sgnorm: 0.0,
            expected_progress: 0.0,
            cnt_descent: 0,
            cnt_null: 0,
            start_time: Instant::now(),
            master: Box::new(BoxedMasterProblem::new(
            master: Box::new(BoxedMasterProblem::new(MinimalMaster::new()?)),
                MinimalMaster::new().map_err(SolverError::Master)?,
            )),
            minorants: vec![],
            iterinfos: vec![],
        })
    }

    /// A new solver with default parameter.
    pub fn new(problem: P) -> Result<Solver<P>, SolverError<P::Err>> {
686
687
688
689
690
691
692
693

694
695
696
697
698
699
700
701
702








703
704
705
706
707
708
709
710
690
691
692
693
694
695
696

697









698
699
700
701
702
703
704
705

706
707
708
709
710
711
712







-
+
-
-
-
-
-
-
-
-
-
+
+
+
+
+
+
+
+
-







                }
            }
        }

        if !newvars.is_empty() {
            let problem = &mut self.problem;
            let minorants = &self.minorants;
            self.master
            self.master.add_vars(
                .add_vars(
                    &newvars.iter().map(|v| (v.0, v.1, v.2)).collect::<Vec<_>>(),
                    &mut |fidx, minidx, vars| {
                        problem
                            .extend_subgradient(minorants[fidx][minidx].primal.as_ref().unwrap(), vars)
                            .map(DVector)
                            .map_err(|e| e.into())
                    },
                )
                &newvars.iter().map(|v| (v.0, v.1, v.2)).collect::<Vec<_>>(),
                &mut |fidx, minidx, vars| {
                    problem
                        .extend_subgradient(minorants[fidx][minidx].primal.as_ref().unwrap(), vars)
                        .map(DVector)
                        .map_err(|e| e.into())
                },
            )?;
                .map_err(SolverError::Master)?;
            // modify moved variables
            for (index, val) in newvars.iter().filter_map(|v| v.0.map(|i| (i, v.3))) {
                self.cur_y[index] = val;
                self.nxt_y[index] = val;
                self.nxt_d[index] = 0.0;
            }
            // add new variables
770
771
772
773
774
775
776
777

778
779
780
781
782

783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805

806
807

808
809
810

811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829

830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849


850
851
852
853
854
855

856
857
858
859
860
861
862
863
864

865
866
867
868
869
870
871
772
773
774
775
776
777
778

779


780
781

782


783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802

803


804



805

806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822

823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841


842
843
844
845
846
847
848

849
850
851
852
853
854
855
856
857

858
859
860
861
862
863
864
865







-
+
-
-


-
+
-
-




















-
+
-
-
+
-
-
-
+
-

















-
+


















-
-
+
+





-
+








-
+







     * information.
     */
    fn init_master(&mut self) -> Result<(), SolverError<P::Err>> {
        let m = self.problem.num_subproblems();

        self.master = if m == 1 && self.params.max_bundle_size == 2 {
            debug!("Use minimal master problem");
            Box::new(BoxedMasterProblem::new(
            Box::new(BoxedMasterProblem::new(MinimalMaster::new()?))
                MinimalMaster::new().map_err(SolverError::Master)?,
            ))
        } else {
            debug!("Use CPLEX master problem");
            Box::new(BoxedMasterProblem::new(
            Box::new(BoxedMasterProblem::new(CplexMaster::new()?))
                CplexMaster::new().map_err(SolverError::Master)?,
            ))
        };

        let lb = self.problem.lower_bounds().map(DVector);
        let ub = self.problem.upper_bounds().map(DVector);

        if lb
            .as_ref()
            .map(|lb| lb.len() != self.problem.num_variables())
            .unwrap_or(false)
        {
            return Err(SolverError::Dimension);
        }
        if ub
            .as_ref()
            .map(|ub| ub.len() != self.problem.num_variables())
            .unwrap_or(false)
        {
            return Err(SolverError::Dimension);
        }

        self.master.set_num_subproblems(m).map_err(SolverError::Master)?;
        self.master.set_num_subproblems(m)?;
        self.master
            .set_vars(self.problem.num_variables(), lb, ub)
        self.master.set_vars(self.problem.num_variables(), lb, ub)?;
            .map_err(SolverError::Master)?;
        self.master
            .set_max_updates(self.params.max_updates)
        self.master.set_max_updates(self.params.max_updates)?;
            .map_err(SolverError::Master)?;

        self.minorants = (0..m).map(|_| vec![]).collect();

        self.cur_val = 0.0;
        for i in 0..m {
            let result = self
                .problem
                .evaluate(i, &self.cur_y, INFINITY, 0.0)
                .map_err(SolverError::Evaluation)?;
            self.cur_vals[i] = result.objective();
            self.cur_val += self.cur_vals[i];

            let mut minorants = result.into_iter();
            if let Some((minorant, primal)) = minorants.next() {
                self.cur_mods[i] = minorant.constant;
                self.cur_mod += self.cur_mods[i];
                self.minorants[i].push(MinorantInfo {
                    index: self.master.add_minorant(i, minorant).map_err(SolverError::Master)?,
                    index: self.master.add_minorant(i, minorant)?,
                    multiplier: 0.0,
                    primal: Some(primal),
                });
            } else {
                return Err(SolverError::NoMinorant);
            }
        }

        self.cur_valid = true;

        // Solve the master problem once to compute the initial
        // subgradient.
        //
        // We could compute that subgradient directly by
        // adding up the initial minorants, but this would not include
        // the eta terms. However, this is a heuristic anyway because
        // we assume an initial weight of 1.0, which, in general, will
        // *not* be the initial weight for the first iteration.
        self.master.set_weight(1.0).map_err(SolverError::Master)?;
        self.master.solve(self.cur_val).map_err(SolverError::Master)?;
        self.master.set_weight(1.0)?;
        self.master.solve(self.cur_val)?;
        self.sgnorm = self.master.get_dualoptnorm2().sqrt();

        // Compute the real initial weight.
        let state = current_state!(self, Step::Term);
        let new_weight = self.weighter.weight(&state, &self.params);
        self.master.set_weight(new_weight).map_err(SolverError::Master)?;
        self.master.set_weight(new_weight)?;

        debug!("Init master completed");

        Ok(())
    }

    /// Solve the model (i.e. master problem) to compute the next candidate.
    fn solve_model(&mut self) -> Result<(), SolverError<P::Err>> {
        self.master.solve(self.cur_val).map_err(SolverError::Master)?;
        self.master.solve(self.cur_val)?;
        self.nxt_d = self.master.get_primopt();
        self.nxt_y.add(&self.cur_y, &self.nxt_d);
        self.nxt_mod = self.master.get_primoptval();
        self.sgnorm = self.master.get_dualoptnorm2().sqrt();
        self.expected_progress = self.cur_val - self.nxt_mod;

        // update multiplier from master solution
889
890
891
892
893
894
895
896

897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914

915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931

932
933
934
935
936
937
938
883
884
885
886
887
888
889

890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907

908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924

925
926
927
928
929
930
931
932







-
+

















-
+
















-
+







            if n >= self.params.max_bundle_size {
                // aggregate minorants with smallest coefficients
                self.minorants[i].sort_by_key(|m| -((1e6 * m.multiplier) as isize));
                let aggr = self.minorants[i].split_off(self.params.max_bundle_size - 2);
                let aggr_sum = aggr.iter().map(|m| m.multiplier).sum();
                let (aggr_mins, aggr_primals): (Vec<_>, Vec<_>) =
                    aggr.into_iter().map(|m| (m.index, m.primal.unwrap())).unzip();
                let (aggr_min, aggr_coeffs) = self.master.aggregate(i, &aggr_mins).map_err(SolverError::Master)?;
                let (aggr_min, aggr_coeffs) = self.master.aggregate(i, &aggr_mins)?;
                // append aggregated minorant
                self.minorants[i].push(MinorantInfo {
                    index: aggr_min,
                    multiplier: aggr_sum,
                    primal: Some(
                        self.problem
                            .aggregate_primals(aggr_coeffs.into_iter().zip(aggr_primals.into_iter()).collect()),
                    ),
                });
            }
        }
        Ok(())
    }

    /// Perform a descent step.
    fn descent_step(&mut self) -> Result<(), SolverError<P::Err>> {
        let new_weight = self.weighter.weight(&current_state!(self, Step::Descent), &self.params);
        self.master.set_weight(new_weight).map_err(SolverError::Master)?;
        self.master.set_weight(new_weight)?;
        self.cnt_descent += 1;
        swap(&mut self.cur_y, &mut self.nxt_y);
        swap(&mut self.cur_val, &mut self.nxt_val);
        swap(&mut self.cur_mod, &mut self.nxt_mod);
        swap(&mut self.cur_vals, &mut self.nxt_vals);
        swap(&mut self.cur_mods, &mut self.nxt_mods);
        self.master.move_center(1.0, &self.nxt_d);
        debug!("Descent Step");
        debug!("  dir ={}", self.nxt_d);
        debug!("  newy={}", self.cur_y);
        Ok(())
    }

    /// Perform a null step.
    fn null_step(&mut self) -> Result<(), SolverError<P::Err>> {
        let new_weight = self.weighter.weight(&current_state!(self, Step::Null), &self.params);
        self.master.set_weight(new_weight).map_err(SolverError::Master)?;
        self.master.set_weight(new_weight)?;
        self.cnt_null += 1;
        debug!("Null Step");
        Ok(())
    }

    /// Perform one bundle iteration.
    #[cfg_attr(feature = "cargo-clippy", allow(collapsible_if))]
985
986
987
988
989
990
991
992
993
994

995
996
997
998
999
1000
1001
1002
979
980
981
982
983
984
985



986

987
988
989
990
991
992
993







-
-
-
+
-







            nxt_ub += fun_ub;
            self.nxt_vals[fidx] = fun_ub;

            // move center of minorant to cur_y
            nxt_minorant.move_center(-1.0, &self.nxt_d);
            self.new_cutval += nxt_minorant.constant;
            self.minorants[fidx].push(MinorantInfo {
                index: self
                    .master
                    .add_minorant(fidx, nxt_minorant)
                index: self.master.add_minorant(fidx, nxt_minorant)?,
                    .map_err(SolverError::Master)?,
                multiplier: 0.0,
                primal: Some(nxt_primal),
            });
        }

        if self.new_cutval > self.cur_val + 1e-3 {
            warn!(