knotkit/kk.cpp

781 lines
19 KiB
C++

#include <knotkit.h>
#include <periodicity.h>
#include <fstream>
#include <sstream>
#include <vector>
#include <utility>
#include <cctype>
const char *program_name;
void
usage ()
{
std::cout << "usage: %s <invariant> [options...] <link>\n" << program_name << "\n"
<< " compute <invariant> for knot or link <link>\n"
<< "<invariant> can be one of:\n"
<< " kh: Khovanov homology\n"
<< " gss: Szabo's geometric spectral sequence\n"
<< " lsss: Batson-Seed link splitting spectral sequence\n"
<< " component weights are 0, 1, ..., m\n"
<< " sq2: Lipshitz-Sarkar Steenrod square on Z/2 Kh\n"
<< " output suitable for Sage\n"
<< " leess: spectral sequence coming from Bar-Natan analogue of Lee's\n"
<< " deformation of Khovanov's complex (whew!)\n"
<< " s: Rasmussen's s-invariant coming from lee\n"
<< " khp: computes Khovanov polynomial of a link\n"
<< " jones: computes Jones polynomial of a link\n"
<< " periodicity: uses periodicity criterion of Przytycki and\n"
<< " the criterion in terms of Khovanov polynomial\n"
<< "output:\n"
<< " kh, gss, lsss, leess: .tex file\n"
<< " sq2: text in Sage format\n"
<< " s, khp, jones, periodicity: text\n"
<< "options:\n"
<< " -r : compute reduced theory\n"
<< " -h : print this message\n"
<< " -o <file> : write output to <file>\n"
<< " (stdout is the default)\n"
<< " -f <field> : ground field (if applicable)\n"
<< " (Z2 is the default)\n"
<< " -v : verbose: report progress as the computation proceeds\n"
<< " -p : period when verifying periodicity, can be equal to\n"
<< " 5,7,11,13,17 or 19\n"
<< " -t : type of periodicity test:\n"
<< " - Przytycki - Przytycki's periodicity test\n"
<< " - Kh - periodicity criterion in terms of Khovanov homology\n"
<< " - all - uses both criteria and tests for all prime\n"
<< " periods between 5 and 19\n"
<< "<field> can be one of:\n"
<< " Z2, Z3, Q\n"
<< "<link> can be one of:\n"
<< " - the unknot, e.g. U or unknot\n"
<< " - a torus knot, e.g. T(2,3)\n"
<< " - a Rolfsen table knot, e.g. 10_124\n"
<< " - a Hoste-Thistlethwaite-Weeks knot, e.g. 11a12 or 12n214\n"
<< " - a Morwen Thistlethwaite link, e.g. L8n9 or L13n8862\n"
<< " - a planar diagram, e.g.\n"
<< " PD[X[1, 4, 2, 5], X[3, 6, 4, 1], X[5, 2, 6, 3]] or\n"
<< " PD[[1, 4, 2, 5], [3, 6, 4, 1], [5, 2, 6, 3]]\n"
<< " - a Dowker-Thistlethwaite code, e.g.\n"
<< " DTCode[6,8,2,4],\n"
<< " DT[dadbcda] or\n"
<< " DT[{6, -8}, {-10, 12, -14, 2, -4}]\n"
<< " - a braid, e.g. BR[2, {-1, -1, -1}]\n"
<< " - disjoint union (juxtaposition), e.g. T(2,3) U\n";
}
FILE *outfp = stdout;
void tex_header ()
{
fprintf (outfp, "\\documentclass{article}\n\
\\usepackage{amsmath, tikz, hyperref}\n\
\\DeclareMathOperator{\\rank}{rank}\n\
\\setlength{\\parindent}{0pt}\n\
\n\
\\begin{document}\n\
\\pagestyle{empty}\n\
\\sloppy\n");
}
void tex_footer ()
{
fprintf (outfp, "\\end{document}\n");
}
const char *knot = 0;
const char *invariant = 0;
const char *field = "Z2";
knot_diagram kd;
bool reduced = 0;
extern int period;
extern std::string periodicity_test;
class hg_grading_mapper
{
unsigned m;
public:
hg_grading_mapper (unsigned m_) : m(m_) { }
grading operator () (grading hq) const
{
int t = hq.q - (int)m;
if (reduced)
t --;
assert (is_even (t));
return grading (hq.h, t / 2);
}
grading map_delta (grading d_hq) const
{
assert (is_even (d_hq.q));
return grading (d_hq.h, d_hq.q / 2);
}
void x_label (FILE *fp, int h) const
{
fprintf (fp, "%d", h);
}
void y_label (FILE *fp, int g) const
{
unsigned q = 2*g + (int)m;
if (reduced)
q ++;
fprintf (fp, "%d", q);
}
};
template<class R> mod_map<R>
compute_link_splitting_d (knot_diagram &kd,
cube<R> &c,
basedvector<R, 1> comp_weight)
{
unsigned n = kd.num_components ();
unionfind<1> u (kd.num_edges ());
for (unsigned i = 1; i <= kd.n_crossings; i ++)
{
u.join (kd.ept_edge (kd.crossings[i][1]),
kd.ept_edge (kd.crossings[i][3]));
u.join (kd.ept_edge (kd.crossings[i][2]),
kd.ept_edge (kd.crossings[i][4]));
}
map<unsigned, unsigned> root_comp;
unsigned t = 0;
for (unsigned i = 1; i <= kd.num_edges (); i ++)
{
if (u.find (i) == i)
{
++ t;
root_comp.push (i, t);
}
}
assert (t == n);
assert (comp_weight.size () == n);
map<unsigned, R> crossing_over_sign;
// crossings
set<unsigned> pending;
set<unsigned> finished;
crossing_over_sign.push (1, R (1));
pending.push (1);
while (pending.card () > 0)
{
unsigned x = pending.pop ();
finished.push (x);
R s = crossing_over_sign(x);
for (unsigned j = 1; j <= 4; j ++)
{
unsigned p = kd.crossings[x][j];
R t = kd.is_over_ept (p) ? s : -s; // sign of (x, p)
unsigned q = kd.edge_other_ept (p);
unsigned x2 = kd.ept_crossing[q];
R u = kd.is_over_ept (q) ? -t : t;
if (crossing_over_sign % x2)
assert (crossing_over_sign(x2) == u);
else
crossing_over_sign.push (x2, u);
if (! (finished % x2))
pending += x2;
}
}
assert (finished.card () == kd.n_crossings);
mod_map<R> untwisted_d = c.compute_d (1, 0, 0, 0, 0);
assert (untwisted_d.compose (untwisted_d) == 0);
mod_map<R> d = untwisted_d;
for (unsigned x = 1; x <= kd.n_crossings; x ++)
{
unsigned p1 = kd.crossings[x][1],
p2 = kd.crossings[x][2];
assert (kd.is_over_ept (p2));
unsigned r1 = u.find (kd.ept_edge (p1)),
r2 = u.find (kd.ept_edge (p2));
unsigned c1 = root_comp(r1),
c2 = root_comp(r2);
if (c1 != c2)
{
R s = crossing_over_sign(x);
R w_under = comp_weight[c1];
R w_over = comp_weight[c2];
d = d + c.compute_dinv (x)*(s*(w_over - w_under));
}
}
assert (d.compose (d) == 0);
return d;
}
void
compute_gss ()
{
cube<Z2> c (kd, reduced);
ptr<const module<Z2> > C = c.khC;
mod_map<Z2> d = c.compute_d (0, 0, 0, 0, 0);
unsigned m = kd.num_components ();
hg_grading_mapper mapper (m);
sseq_bounds b (C, mapper);
basedvector<sseq_page, 1> pages;
unsigned k = 1;
for (;;)
{
chain_complex_simplifier<Z2> s (C, d,
maybe<int> (k), maybe<int> (2*k - 2));
C = s.new_C;
d = s.new_d;
k ++;
grading dk_gr (k, 2*k - 2);
pages.append (sseq_page (b, k, dk_gr, d.graded_piece (dk_gr), mapper));
if (d == 0)
break;
}
sseq ss (b, pages);
tex_header ();
fprintf (outfp, "$E_k = %s^{Sz}_k(\\verb~%s~; \\verb~%s~)$:\\\\\n",
(reduced
? "\\widetilde{E}"
: "E"),
knot, field);
ss.texshow (outfp, mapper);
tex_footer ();
}
template<class R>
multivariate_laurentpoly<Z> compute_khp(const knot_diagram& k, bool reduced = false) {
cube<R> c (kd, reduced);
ptr<const module<R> > C = c.khC;
mod_map<R> d = c.compute_d (1, 0, 0, 0, 0);
unsigned m = kd.num_components ();
hg_grading_mapper mapper (m);
chain_complex_simplifier<R> s (C, d,
maybe<int> (1), maybe<int> (0));
C = s.new_C;
d = s.new_d;
return C->free_poincare_polynomial();
}
multivariate_laurentpoly<Z> compute_jones(const knot_diagram& k, bool reduced = false) {
return compute_khp<Z2>(k, reduced).evaluate(-1, 1);
}
template<class R>
int compute_s_inv(knot_diagram& kd) {
unsigned m = kd.num_components ();
if (m != 1) {
fprintf (stderr, "error: s-invariant only defined for knots\n");
exit (EXIT_FAILURE);
}
cube<R> c (kd, 0);
ptr<const module<R> > C = c.khC;
mod_map<R> d = c.compute_d (1, 0, 0, 0, 0);
for (unsigned i = 1; i <= kd.n_crossings; i ++)
d = d + c.H_i (i);
assert (d.compose (d) == 0);
int k = 0;
for (;;) {
chain_complex_simplifier<R> s (C, d,
maybe<int> (1),
maybe<int> (2*k));
C = s.new_C;
d = s.new_d;
k ++;
if (d == 0)
break;
}
assert (C->dim () == 2);
grading gr1 = C->generator_grading (1),
gr2 = C->generator_grading (2);
C->free_poincare_polynomial().display_self();
int qmin = gr1.q,
qmax = gr2.q;
if (qmax < qmin)
std::swap (qmin, qmax);
assert (qmax == qmin + 2);
return qmin + 1;
}
template<class R> void
compute_invariant ()
{
if (!strcmp (invariant, "kh"))
{
cube<R> c (kd, reduced);
ptr<const module<R> > C = c.khC;
mod_map<R> d = c.compute_d (1, 0, 0, 0, 0);
unsigned m = kd.num_components ();
hg_grading_mapper mapper (m);
chain_complex_simplifier<R> s (C, d,
maybe<int> (1), maybe<int> (0));
C = s.new_C;
d = s.new_d;
sseq_bounds b (C, mapper);
sseq_page pg (b, 2, grading (0, 0), mod_map<R> (C), mapper);
tex_header ();
fprintf (outfp, "Kh = $%s(\\verb~%s~; \\verb~%s~)$:\\\\\n",
(reduced
? "\\widetilde{Kh}"
: "Kh"),
knot,
field);
fprintf (outfp, "$\\rank Kh = %d$\\\\\n", C->dim ());
char buf[1000];
sprintf (buf, "$Kh$");
pg.texshow (outfp, b, buf, mapper);
tex_footer ();
}
else if (!strcmp (invariant, "lsss"))
{
cube<R> c (kd, reduced);
ptr<const module<R> > C = c.khC;
unsigned m = kd.num_components ();
basedvector<R, 1> comp_weight (m);
for (unsigned i = 1; i <= m; i ++)
comp_weight[i] = R ((int)(i - 1));
mod_map<R> d = compute_link_splitting_d (kd, c, comp_weight);
hg_grading_mapper mapper (m);
sseq_bounds b (C, mapper);
basedvector<sseq_page, 1> pages;
int k = 0;
for (;;)
{
chain_complex_simplifier<R> s (C, d,
maybe<int> (1 - 2*k), maybe<int> (-2*k));
C = s.new_C;
d = s.new_d;
k ++;
grading dk_gr (1 - 2*k, -2*k);
pages.append (sseq_page (b, k, dk_gr, d.graded_piece (dk_gr), mapper));
if (d == 0)
break;
}
sseq ss (b, pages);
tex_header ();
fprintf (outfp, "$E_k = %s^{BS}_k({}^{%d}\\verb~%s~; \\verb~%s~)$:\\\\\n",
(reduced
? "\\widetilde{E}"
: "E"),
m,
knot,
field);
ss.texshow (outfp, mapper);
tex_footer ();
}
else if (!strcmp (invariant, "leess")) {
cube<R> c (kd, reduced);
ptr<const module<R> > C = c.khC;
mod_map<R> d = c.compute_d (1, 0, 0, 0, 0);
for (unsigned i = 1; i <= kd.n_crossings; i ++)
d = d + c.H_i (i);
assert (d.compose (d) == 0);
unsigned m = kd.num_components ();
hg_grading_mapper mapper (m);
sseq_bounds b (C, mapper);
basedvector<sseq_page, 1> pages;
int k = 0;
for (;;) {
chain_complex_simplifier<R> s (C, d,
maybe<int> (1), maybe<int> (2*k));
C = s.new_C;
d = s.new_d;
k ++;
grading dk_gr (1, 2*k);
pages.append (sseq_page (b, k, dk_gr, d.graded_piece (dk_gr), mapper));
if (d == 0)
break;
}
sseq ss (b, pages);
tex_header ();
fprintf (outfp, "$E_k = %s^{BN}_k(\\verb~%s~; \\verb~%s~)$:\\\\\n",
(reduced
? "\\widetilde{E}"
: "E"),
knot, field);
ss.texshow (outfp, mapper);
tex_footer ();
}
else if (!strcmp (invariant, "s"))
{
int s = compute_s_inv<R>(kd);
fprintf (outfp, "s(%s; %s) = %d\n", knot, field, s);
}
else {
fprintf (stderr, "error: unknown invariant %s\n", invariant);
exit (EXIT_FAILURE);
}
}
void
sage_show (FILE *fp,
map<grading, basedvector<unsigned, 1> > hq_gens,
ptr<const module<Z2> > H)
{
fprintf (fp, "hom={");
bool first = 1;
for (map<grading, basedvector<unsigned, 1> >::const_iter i = hq_gens; i; i ++)
{
if (first)
first = 0;
else
fprintf (fp, ", ");
fprintf (fp, "(%d, %d): %d", i.key ().h, i.key ().q, i.val ().size ());
}
fprintf (fp, "}\n");
}
void
sage_show (FILE *fp,
map<grading, basedvector<unsigned, 1> > hq_gens,
std::string name,
grading delta,
mod_map<Z2> f)
{
fprintf (fp, "%s={", name.c_str ());
bool first = 1;
for (map<grading, basedvector<unsigned, 1> >::const_iter i = hq_gens; i; i ++)
{
grading from_hq = i.key ();
basedvector<unsigned, 1> from_gens = i.val ();
grading to_hq = from_hq + delta;
if (hq_gens % to_hq)
{
basedvector<unsigned, 1> to_gens = hq_gens(to_hq);
if (first)
first = 0;
else
fprintf (fp, ", ");
fprintf (fp, "(%d, %d): [", from_hq.h, from_hq.q);
bool first2 = 1;
for (unsigned j = 1; j <= from_gens.size (); j ++)
{
unsigned gj = from_gens[j];
if (first2)
first2 = 0;
else
fprintf (fp, ", ");
fprintf (fp, "(");
for (unsigned k = 1; k <= to_gens.size (); k ++)
{
unsigned gk = to_gens[k];
if (k > 1)
fprintf (fp, ", ");
if (f[gj](gk) == 1)
fprintf (fp, "1");
else
{
assert (f[gj](gk) == 0);
fprintf (fp, "0");
}
}
fprintf (fp, ")");
}
fprintf (fp, "]");
}
}
fprintf (fp, "}\n");
}
void
sage_show_khsq (FILE *fp,
ptr<const module<Z2> > H,
mod_map<Z2> sq1,
mod_map<Z2> sq2)
{
unsigned n = H->dim ();
map<grading, basedvector<unsigned, 1> > hq_gens;
for (unsigned i = 1; i <= H->dim (); i ++)
hq_gens[H->generator_grading (i)].append (i);
unsigned t = 0;
for (map<grading, basedvector<unsigned, 1> >::const_iter i = hq_gens; i; i ++)
t += i.val ().size ();
assert (t == n);
sage_show (fp, hq_gens, H);
sage_show (fp, hq_gens, "sq1", grading (1, 0), sq1);
sage_show (fp, hq_gens, "sq2", grading (2, 0), sq2);
}
void
compute_sq2 ()
{
cube<Z2> c (kd);
mod_map<Z2> d = c.compute_d (1, 0, 0, 0, 0);
chain_complex_simplifier<Z2> s (c.khC, d, maybe<int> (1), maybe<int> (0));
assert (s.new_d == 0);
steenrod_square sq (c, d, s);
mod_map<Z2> sq1 = sq.sq1 ();
mod_map<Z2> sq2 = sq.sq2 ();
ptr<const module<Z2> > H = sq1.domain ();
sage_show_khsq (outfp, H, sq1, sq2);
}
unsigned
kh_rk (knot_diagram kd)
{
cube<Z2> c (kd);
mod_map<Z2> d = c.compute_d (1, 0, 0, 0, 0);
chain_complex_simplifier<Z2> s (c.khC, d, maybe<int> (1), maybe<int> (0));
assert (s.new_d == 0);
return s.new_C->free_rank();
}
void
run_demo ()
{
printf ("Link \t\t L1 \t L2 \t L \n");
for (unsigned i = 10; i <= 11; i ++)
{
for (unsigned j = 90; j <= fmin(mt_links (i, 0), 230); j ++)
{
knot_diagram kd (mt_link (i, 0, j));
if (kd.num_components () != 2)
continue;
knot_diagram L1 (SUBLINK, smallbitset (2, 1), kd);
knot_diagram L2 (SUBLINK, smallbitset (2, 2), kd);
printf ("%s \t %d \t %d \t %d \n", kd.name.c_str(), kh_rk(L1), kh_rk(L2), kh_rk(kd));
}
}
}
int
main (int argc, char **argv)
{
program_name = argv[0];
const char *file = 0;
for (int i = 1; i < argc; i ++) {
if (argv[i][0] == '-') {
if (strcmp (argv[i], "-r") == 0)
reduced = 1;
else if (strcmp (argv[i], "-h") == 0) {
usage ();
exit (EXIT_SUCCESS);
}
else if (strcmp (argv[i], "-demo") == 0) {
run_demo();
exit (EXIT_SUCCESS);
}
else if (!strcmp (argv[i], "-v"))
verbose = 1;
else if (!strcmp (argv[i], "-f")) {
i ++;
if (i == argc) {
fprintf (stderr, "error: missing argument to option `-f'\n");
exit (EXIT_FAILURE);
}
field = argv[i];
}
else if (!strcmp (argv[i], "-o")) {
i ++;
if (i == argc) {
fprintf (stderr, "error: missing argument to option `-o'\n");
exit (EXIT_FAILURE);
}
file = argv[i];
}
else if(!strcmp (argv[i], "-p")) {
i++;
if(i == argc) {
fprintf (stderr, "error: missing argument to option `-p'\n");
exit (EXIT_FAILURE);
}
period = std::stoi(argv[i]);
}
else if (!strcmp(argv[i], "-t")) {
i++;
if(i == argc) {
fprintf (stderr, "error: missing argument to option `-t'\n");
exit (EXIT_FAILURE);
}
periodicity_test = argv[i];
}
else {
fprintf (stderr, "error: unknown argument `%s'\n", argv[1]);
fprintf (stderr, " use -h for usage\n");
exit (EXIT_FAILURE);
}
}
else {
if (knot) {
fprintf (stderr, "error: too many arguments\n");
fprintf (stderr, " use -h for usage\n");
exit (EXIT_FAILURE);
}
else if (invariant)
knot = argv[i];
else {
assert (invariant == 0);
invariant = argv[i];
}
}
}
if (!knot)
{
fprintf (stderr, "error: too few arguments, <invariant> or <knot> missing\n");
fprintf (stderr, " use -h for usage\n");
exit (EXIT_FAILURE);
}
if (file) {
outfp = fopen (file, "w");
if (!outfp) {
stderror ("fopen: %s", file);
exit (EXIT_FAILURE);
}
}
else
outfp = stdout;
kd = parse_knot (knot);
kd.marked_edge = 1;
if (!strcmp (invariant, "gauss")) {
basedvector<basedvector<int, 1>, 1> gc = kd.as_gauss_code ();
for (unsigned i = 1; i <= gc.size (); i ++) {
if (i > 1)
printf (":");
for (unsigned j = 1; j <= gc[i].size (); j ++) {
if (j > 1)
printf (",");
printf ("%d", gc[i][j]);
}
}
newline ();
}
if (!strcmp (invariant, "sq2")) {
if (strcmp (field, "Z2")) {
fprintf (stderr, "warning: sq2 only defined over Z2, ignoring -f %s\n", field);
field = "Z2";
}
compute_sq2 ();
}
else if (!strcmp (invariant, "gss")) {
if (strcmp (field, "Z2")) {
fprintf (stderr, "warning: gss only defined over Z2, ignoring -f %s\n", field);
field = "Z2";
}
compute_gss ();
}
else if(!strcmp(invariant, "jones")) {
std::cout << "Jones polynomial of " << knot << " = " << compute_jones(kd, reduced) << "\n";
}
else if(!strcmp(invariant, "periodicity")) {
check_periodicity(kd, std::string(knot), period, std::string(field));
}
else if(!strcmp(invariant, "khp")) {
multivariate_laurentpoly<Z> khp;
if(!strcmp(field, "Z2"))
khp = compute_khp<Z2>(kd, reduced);
else if(!strcmp(field, "Z3"))
khp = compute_khp<Zp<3>>(kd, reduced);
else if(!strcmp(field, "Z5"))
khp = compute_khp<Zp<5>>(kd, reduced);
else if (!strcmp(field, "Z7"))
khp = compute_khp<Zp<7>>(kd,reduced);
else if(!strcmp(field, "Q"))
khp = compute_khp<Q>(kd, reduced);
else
{
std::cerr << "Unknown field: " << field << std::endl;
exit (EXIT_FAILURE);
}
std::cout << "Khovanov polynomial (coefficients in " << field
<< ") of " << knot << " = " << std::endl
<< khp << std::endl;
}
else {
if (!strcmp (field, "Z2"))
compute_invariant<Z2> ();
else if (!strcmp (field, "Z3"))
compute_invariant<Zp<3>> ();
else if (!strcmp (field, "Q"))
compute_invariant<Q> ();
else {
fprintf (stderr, "error: unknown field %s\n", field);
exit (EXIT_FAILURE);
}
}
if (file)
fclose (outfp);
}