gtsam/gtsam_unstable/discrete/Scheduler.cpp

274 lines
8.7 KiB
C++

/*
* Scheduler.h
* @brief an example how inference can be used for scheduling qualifiers
* @date Mar 26, 2011
* @author Frank Dellaert
*/
#include <gtsam/base/debug.h>
#include <gtsam/base/timing.h>
#include <gtsam/discrete/DiscreteFactorGraph.h>
#include <gtsam_unstable/discrete/Scheduler.h>
#include <boost/tokenizer.hpp>
#include <cmath>
#include <fstream>
#include <iomanip>
#include <cassert>
namespace gtsam {
using namespace std;
Scheduler::Scheduler(size_t maxNrStudents, const string& filename)
: maxNrStudents_(maxNrStudents) {
typedef boost::tokenizer<boost::escaped_list_separator<char> > Tokenizer;
// open file
ifstream is(filename.c_str());
if (!is) {
cerr << "Scheduler: could not open file " << filename << endl;
throw runtime_error("Scheduler: could not open file " + filename);
}
string line; // buffer
// process first line with faculty
if (getline(is, line, '\r')) {
Tokenizer tok(line);
Tokenizer::iterator it = tok.begin();
for (++it; it != tok.end(); ++it) addFaculty(*it);
}
// for all remaining lines
size_t count = 0;
while (getline(is, line, '\r')) {
if (count++ > 100) throw runtime_error("reached 100 lines, exiting");
Tokenizer tok(line);
Tokenizer::iterator it = tok.begin();
addSlot(*it++); // add slot
// add availability
for (; it != tok.end(); ++it) available_ += (it->empty()) ? "0 " : "1 ";
available_ += '\n';
}
} // constructor
/** addStudent has to be called after adding slots and faculty */
void Scheduler::addStudent(const string& studentName, const string& area1,
const string& area2, const string& area3,
const string& advisor) {
assert(nrStudents() < maxNrStudents_);
assert(facultyInArea_.count(area1));
assert(facultyInArea_.count(area2));
assert(facultyInArea_.count(area3));
size_t advisorIndex = facultyIndex_[advisor];
Student student(nrFaculty(), advisorIndex);
student.name_ = studentName;
// We fix the ordering by assigning a higher index to the student
// and numbering the areas lower
Key j = 3 * maxNrStudents_ + nrStudents();
student.key_ = DiscreteKey(j, nrTimeSlots());
Key base = 3 * nrStudents();
student.keys_[0] = DiscreteKey(base + 0, nrFaculty());
student.keys_[1] = DiscreteKey(base + 1, nrFaculty());
student.keys_[2] = DiscreteKey(base + 2, nrFaculty());
student.areaName_[0] = area1;
student.areaName_[1] = area2;
student.areaName_[2] = area3;
students_.push_back(student);
}
/** get key for student and area, 0 is time slot itself */
const DiscreteKey& Scheduler::key(size_t s,
std::optional<size_t> area) const {
return area ? students_[s].keys_[*area] : students_[s].key_;
}
const string& Scheduler::studentName(size_t i) const {
assert(i < nrStudents());
return students_[i].name_;
}
const DiscreteKey& Scheduler::studentKey(size_t i) const {
assert(i < nrStudents());
return students_[i].key_;
}
const string& Scheduler::studentArea(size_t i, size_t area) const {
assert(i < nrStudents());
return students_[i].areaName_[area];
}
/** Add student-specific constraints to the graph */
void Scheduler::addStudentSpecificConstraints(size_t i,
std::optional<size_t> slot) {
bool debug = ISDEBUG("Scheduler::buildGraph");
assert(i < nrStudents());
const Student& s = students_[i];
if (!slot && !slotsAvailable_.empty()) {
if (debug) cout << "Adding availability of slots" << endl;
assert(slotsAvailable_.size() == s.key_.second);
CSP::add(s.key_, slotsAvailable_);
}
// For all areas
for (size_t area = 0; area < 3; area++) {
DiscreteKey areaKey = s.keys_[area];
const string& areaName = s.areaName_[area];
if (debug) cout << "Area constraints " << areaName << endl;
assert(facultyInArea_[areaName].size() == areaKey.second);
CSP::add(areaKey, facultyInArea_[areaName]);
if (debug) cout << "Advisor constraint " << areaName << endl;
assert(s.advisor_.size() == areaKey.second);
CSP::add(areaKey, s.advisor_);
if (debug) cout << "Availability of faculty " << areaName << endl;
if (slot) {
// get all constraints then specialize to slot
size_t dummyIndex = maxNrStudents_ * 3 + maxNrStudents_;
DiscreteKey dummy(dummyIndex, nrTimeSlots());
AlgebraicDecisionTree<Key> p(dummy & areaKey,
available_); // available_ is Doodle string
auto q = p.choose(dummyIndex, *slot);
CSP::add(areaKey, q);
} else {
DiscreteKeys keys {s.key_, areaKey};
CSP::add(keys, available_); // available_ is Doodle string
}
}
// add mutex
if (debug) cout << "Mutex for faculty" << endl;
addAllDiff(s.keys_[0] & s.keys_[1] & s.keys_[2]);
}
/** Main routine that builds factor graph */
void Scheduler::buildGraph(size_t mutexBound) {
bool debug = ISDEBUG("Scheduler::buildGraph");
if (debug) cout << "Adding student-specific constraints" << endl;
for (size_t i = 0; i < nrStudents(); i++) addStudentSpecificConstraints(i);
// special constraint for MN
if (studentName(0) == "Michael N")
CSP::add(studentKey(0), "0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1");
if (!mutexBound) {
DiscreteKeys dkeys;
for (const Student& s : students_) dkeys.push_back(s.key_);
addAllDiff(dkeys);
} else {
if (debug) cout << "Mutex for Students" << endl;
for (size_t i1 = 0; i1 < nrStudents(); i1++) {
// if mutexBound=1, we only mutex with next student
size_t bound = min((i1 + 1 + mutexBound), nrStudents());
for (size_t i2 = i1 + 1; i2 < bound; i2++) {
addAllDiff(studentKey(i1), studentKey(i2));
}
}
}
} // buildGraph
/** print */
void Scheduler::print(const string& s, const KeyFormatter& formatter) const {
cout << s << " Faculty:" << endl;
for (const string& name : facultyName_) cout << name << '\n';
cout << endl;
cout << s << " Slots:\n";
size_t i = 0;
for (const string& name : slotName_) cout << i++ << " " << name << endl;
cout << endl;
cout << "Availability:\n" << available_ << '\n';
cout << s << " Area constraints:\n";
for (const FacultyInArea::value_type& it : facultyInArea_) {
cout << setw(12) << it.first << ": ";
for (double v : it.second) cout << v << " ";
cout << '\n';
}
cout << endl;
cout << s << " Students:\n";
for (const Student& student : students_) student.print();
cout << endl;
CSP::print(s + " Factor graph");
cout << endl;
} // print
/** Print readable form of assignment */
void Scheduler::printAssignment(const DiscreteValues& assignment) const {
// Not intended to be general! Assumes very particular ordering !
cout << endl;
for (size_t s = 0; s < nrStudents(); s++) {
Key j = 3 * maxNrStudents_ + s;
size_t slot = assignment.at(j);
cout << studentName(s) << " slot: " << slotName_[slot] << endl;
Key base = 3 * s;
for (size_t area = 0; area < 3; area++) {
size_t faculty = assignment.at(base + area);
cout << setw(12) << studentArea(s, area) << ": " << facultyName_[faculty]
<< endl;
}
cout << endl;
}
}
/** Special print for single-student case */
void Scheduler::printSpecial(const DiscreteValues& assignment) const {
DiscreteValues::const_iterator it = assignment.begin();
for (size_t area = 0; area < 3; area++, it++) {
size_t f = it->second;
cout << setw(12) << studentArea(0, area) << ": " << facultyName_[f] << endl;
}
cout << endl;
}
/** Accumulate faculty stats */
void Scheduler::accumulateStats(const DiscreteValues& assignment,
vector<size_t>& stats) const {
for (size_t s = 0; s < nrStudents(); s++) {
Key base = 3 * s;
for (size_t area = 0; area < 3; area++) {
size_t f = assignment.at(base + area);
assert(f < stats.size());
stats[f]++;
} // area
} // s
}
/** Eliminate, return a Bayes net */
DiscreteBayesNet::shared_ptr Scheduler::eliminate() const {
gttic(my_eliminate);
// TODO: fix this!!
size_t maxKey = keys().size();
Ordering defaultKeyOrdering;
for (size_t i = 0; i < maxKey; ++i) defaultKeyOrdering.push_back(i);
DiscreteBayesNet::shared_ptr chordal =
this->eliminateSequential(defaultKeyOrdering);
gttoc(my_eliminate);
return chordal;
}
/** find the assignment of students to slots with most possible committees */
DiscreteValues Scheduler::bestSchedule() const {
DiscreteValues best;
throw runtime_error("bestSchedule not implemented");
return best;
}
/** find the corresponding most desirable committee assignment */
DiscreteValues Scheduler::bestAssignment(const DiscreteValues& bestSchedule) const {
DiscreteValues best;
throw runtime_error("bestAssignment not implemented");
return best;
}
} // namespace gtsam