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/**************************************************************************
* *
* Regina - A Normal Surface Theory Calculator *
* Computational Engine *
* *
* Copyright (c) 1999-2011, Ben Burton *
* For further details contact Ben Burton (bab@debian.org). *
* *
* This program is free software; you can redistribute it and/or *
* modify it under the terms of the GNU General Public License as *
* published by the Free Software Foundation; either version 2 of the *
* License, or (at your option) any later version. *
* *
* This program is distributed in the hope that it will be useful, but *
* WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU *
* General Public License for more details. *
* *
* You should have received a copy of the GNU General Public *
* License along with this program; if not, write to the Free *
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, *
* MA 02110-1301, USA. *
* *
**************************************************************************/
/* end stub */
#include "file/nglobaldirs.h"
#include "manifold/nsnappeacensusmfd.h"
#include "subcomplex/nsnappeacensustri.h"
#include "triangulation/nexampletriangulation.h"
#include "triangulation/ntriangulation.h"
#include <cstdio>
#include <cstring>
namespace regina {
namespace {
int homDecode(char c) {
if (c >= 'a' && c <= 'z')
return c - 'a';
if (c >= 'A' && c <= 'Z')
return c - 'A' + 26;
return -1;
}
}
const char NSnapPeaCensusManifold::SEC_5 = 'm';
const char NSnapPeaCensusManifold::SEC_6_OR = 's';
const char NSnapPeaCensusManifold::SEC_6_NOR = 'x';
const char NSnapPeaCensusManifold::SEC_7_OR = 'v';
const char NSnapPeaCensusManifold::SEC_7_NOR = 'y';
NTriangulation* NSnapPeaCensusManifold::construct() const {
NTriangulation* ans = 0;
// Hard-code a few special cases so that the numbering of tetrahedra
// and vertices is compatible with earlier versions of Regina.
if (section == SEC_5) {
if (index == 0) {
ans = NExampleTriangulation::gieseking();
ans->setPacketLabel("");
} else if (index == 1) {
ans = new NTriangulation();
NTetrahedron* r = ans->newTetrahedron();
NTetrahedron* s = ans->newTetrahedron();
r->joinTo(0, s, NPerm4(0, 1, 3, 2));
r->joinTo(1, s, NPerm4(2, 3, 1, 0));
r->joinTo(2, s, NPerm4(3, 2, 1, 0));
r->joinTo(3, s, NPerm4(1, 0, 3, 2));
} else if (index == 2) {
ans = new NTriangulation();
NTetrahedron* r = ans->newTetrahedron();
NTetrahedron* s = ans->newTetrahedron();
r->joinTo(0, s, NPerm4(0, 1, 3, 2));
r->joinTo(1, s, NPerm4(3, 1, 2, 0));
r->joinTo(2, s, NPerm4(2, 1, 3, 0));
r->joinTo(3, s, NPerm4(3, 1, 0, 2));
} else if (index == 3) {
ans = new NTriangulation();
NTetrahedron* r = ans->newTetrahedron();
NTetrahedron* s = ans->newTetrahedron();
r->joinTo(0, s, NPerm4(0, 1, 3, 2));
r->joinTo(1, s, NPerm4(2, 1, 0, 3));
r->joinTo(2, s, NPerm4(0, 3, 2, 1));
r->joinTo(3, s, NPerm4(1, 0, 2, 3));
} else if (index == 4) {
ans = NExampleTriangulation::figureEightKnotComplement();
ans->setPacketLabel("");
} else if (index == 129) {
ans = NExampleTriangulation::whiteheadLinkComplement();
ans->setPacketLabel("");
}
}
if (ans)
return ans;
// Fetch the relevant data from the census dehydration files.
std::string file = NGlobalDirs::data();
switch (section) {
case SEC_5:
file += "/snappea-census-sec5.dat"; break;
case SEC_6_OR:
file += "/snappea-census-sec6o.dat"; break;
case SEC_6_NOR:
file += "/snappea-census-sec6n.dat"; break;
case SEC_7_OR:
file += "/snappea-census-sec7o.dat"; break;
case SEC_7_NOR:
file += "/snappea-census-sec7n.dat"; break;
default:
return 0;
}
FILE* dat = fopen(file.c_str(), "r");
if (! dat) {
std::cerr << "Cannot open data file: " << file << std::endl;
return 0;
}
char tri[30], hom[30]; /* Long enough to deal with the snappea census
files for <= 7 tetrahedra. */
for (unsigned i = 0; i <= index; ++i) {
if (fscanf(dat, "%s%s", tri, hom) != 2) {
if (feof(dat))
std::cerr << "Read beyond end of data file: "
<< file << std::endl;
else
std::cerr << "Error reading data file: " << file << std::endl;
return 0;
}
}
fclose(dat);
ans = NTriangulation::rehydrate(tri);
return ans;
}
NAbelianGroup* NSnapPeaCensusManifold::getHomologyH1() const {
// Fetch the relevant data from the census dehydration files.
std::string file = NGlobalDirs::data();
switch (section) {
case SEC_5:
file += "/snappea-census-sec5.dat"; break;
case SEC_6_OR:
file += "/snappea-census-sec6o.dat"; break;
case SEC_6_NOR:
file += "/snappea-census-sec6n.dat"; break;
case SEC_7_OR:
file += "/snappea-census-sec7o.dat"; break;
case SEC_7_NOR:
file += "/snappea-census-sec7n.dat"; break;
default:
return 0;
}
FILE* dat = fopen(file.c_str(), "r");
if (! dat) {
std::cerr << "Cannot open data file: " << file << std::endl;
return 0;
}
char tri[30], hom[30]; /* Long enough to deal with the snappea census
files for <= 7 tetrahedra. */
for (unsigned i = 0; i <= index; ++i) {
if (fscanf(dat, "%s%s", tri, hom) != 2) {
if (feof(dat))
std::cerr << "Read beyond end of data file: "
<< file << std::endl;
else
std::cerr << "Error reading data file: " << file << std::endl;
return 0;
}
}
fclose(dat);
NAbelianGroup* ans = new NAbelianGroup();
char* c;
int val;
// First character of the homology string represents rank.
val = homDecode(hom[0]); // Empty string is picked up and dealt with here.
if (val < 0) {
delete ans;
return 0;
}
ans->addRank(val);
// The remaining characters represent torsion.
std::multiset<NLargeInteger> torsion;
for (c = hom + 1; *c; ++c) {
val = homDecode(*c);
if (val < 0) {
delete ans;
return 0;
}
torsion.insert(val);
}
ans->addTorsionElements(torsion);
return ans;
}
std::ostream& NSnapPeaCensusManifold::writeName(std::ostream& out) const {
// Some manifolds will get special names, and will have their usual
// SnapPea names written in writeStructure() instead.
if (section == SEC_5) {
if (index == 0)
return out << "Gieseking manifold";
if (index == 4)
return out << "Figure eight knot complement";
if (index == 129)
return out << "Whitehead link complement";
}
// No special names, just the usual SnapPea notation.
return NSnapPeaCensusTri(section, index).writeName(out);
}
std::ostream& NSnapPeaCensusManifold::writeTeXName(std::ostream& out) const {
return NSnapPeaCensusTri(section, index).writeTeXName(out);
}
std::ostream& NSnapPeaCensusManifold::writeStructure(std::ostream& out) const {
// If we didn't give the usual SnapPea name in writeName(), give it here.
if (section == SEC_5) {
if (index == 0 || index == 4 || index == 129)
return NSnapPeaCensusTri(section, index).writeName(out);
}
return out;
}
} // namespace regina
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