3 * Implementation of GiNaC's indices. */
6 * GiNaC Copyright (C) 1999-2003 Johannes Gutenberg University Mainz, Germany
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
30 #include "relational.h"
31 #include "operators.h"
38 GINAC_IMPLEMENT_REGISTERED_CLASS(idx, basic)
39 GINAC_IMPLEMENT_REGISTERED_CLASS(varidx, idx)
40 GINAC_IMPLEMENT_REGISTERED_CLASS(spinidx, varidx)
43 // default ctor, dtor, copy ctor, assignment operator and helpers
46 idx::idx() : inherited(TINFO_idx) {}
48 varidx::varidx() : covariant(false)
50 tinfo_key = TINFO_varidx;
53 spinidx::spinidx() : dotted(false)
55 tinfo_key = TINFO_spinidx;
58 void idx::copy(const idx & other)
60 inherited::copy(other);
65 void varidx::copy(const varidx & other)
67 inherited::copy(other);
68 covariant = other.covariant;
71 void spinidx::copy(const spinidx & other)
73 inherited::copy(other);
74 dotted = other.dotted;
78 DEFAULT_DESTROY(varidx)
79 DEFAULT_DESTROY(spinidx)
85 idx::idx(const ex & v, const ex & d) : inherited(TINFO_idx), value(v), dim(d)
88 if (!dim.info(info_flags::posint))
89 throw(std::invalid_argument("dimension of space must be a positive integer"));
92 varidx::varidx(const ex & v, const ex & d, bool cov) : inherited(v, d), covariant(cov)
94 tinfo_key = TINFO_varidx;
97 spinidx::spinidx(const ex & v, const ex & d, bool cov, bool dot) : inherited(v, d, cov), dotted(dot)
99 tinfo_key = TINFO_spinidx;
106 idx::idx(const archive_node &n, lst &sym_lst) : inherited(n, sym_lst)
108 n.find_ex("value", value, sym_lst);
109 n.find_ex("dim", dim, sym_lst);
112 varidx::varidx(const archive_node &n, lst &sym_lst) : inherited(n, sym_lst)
114 n.find_bool("covariant", covariant);
117 spinidx::spinidx(const archive_node &n, lst &sym_lst) : inherited(n, sym_lst)
119 n.find_bool("dotted", dotted);
122 void idx::archive(archive_node &n) const
124 inherited::archive(n);
125 n.add_ex("value", value);
126 n.add_ex("dim", dim);
129 void varidx::archive(archive_node &n) const
131 inherited::archive(n);
132 n.add_bool("covariant", covariant);
135 void spinidx::archive(archive_node &n) const
137 inherited::archive(n);
138 n.add_bool("dotted", dotted);
141 DEFAULT_UNARCHIVE(idx)
142 DEFAULT_UNARCHIVE(varidx)
143 DEFAULT_UNARCHIVE(spinidx)
146 // functions overriding virtual functions from base classes
149 void idx::print(const print_context & c, unsigned level) const
151 if (is_a<print_tree>(c)) {
153 c.s << std::string(level, ' ') << class_name()
154 << std::hex << ", hash=0x" << hashvalue << ", flags=0x" << flags << std::dec
156 unsigned delta_indent = static_cast<const print_tree &>(c).delta_indent;
157 value.print(c, level + delta_indent);
158 dim.print(c, level + delta_indent);
162 if (is_a<print_latex>(c))
166 bool need_parens = !(is_exactly_a<numeric>(value) || is_a<symbol>(value));
172 if (c.options & print_options::print_index_dimensions) {
177 if (is_a<print_latex>(c))
182 void varidx::print(const print_context & c, unsigned level) const
184 if (is_a<print_tree>(c)) {
186 c.s << std::string(level, ' ') << class_name()
187 << std::hex << ", hash=0x" << hashvalue << ", flags=0x" << flags << std::dec
188 << (covariant ? ", covariant" : ", contravariant")
190 unsigned delta_indent = static_cast<const print_tree &>(c).delta_indent;
191 value.print(c, level + delta_indent);
192 dim.print(c, level + delta_indent);
195 if (is_a<print_latex>(c))
203 bool need_parens = !(is_exactly_a<numeric>(value) || is_a<symbol>(value));
209 if (c.options & print_options::print_index_dimensions) {
214 if (is_a<print_latex>(c))
219 void spinidx::print(const print_context & c, unsigned level) const
221 if (is_a<print_tree>(c)) {
223 c.s << std::string(level, ' ') << class_name()
224 << std::hex << ", hash=0x" << hashvalue << ", flags=0x" << flags << std::dec
225 << (covariant ? ", covariant" : ", contravariant")
226 << (dotted ? ", dotted" : ", undotted")
228 unsigned delta_indent = static_cast<const print_tree &>(c).delta_indent;
229 value.print(c, level + delta_indent);
230 dim.print(c, level + delta_indent);
234 bool is_tex = is_a<print_latex>(c);
252 bool need_parens = !(is_exactly_a<numeric>(value) || is_a<symbol>(value));
258 if (is_tex && dotted)
265 bool idx::info(unsigned inf) const
267 if (inf == info_flags::idx)
269 return inherited::info(inf);
272 size_t idx::nops() const
274 // don't count the dimension as that is not really a sub-expression
278 ex idx::op(size_t i) const
280 GINAC_ASSERT(i == 0);
284 ex idx::map(map_function & f) const
286 idx *copy = static_cast<idx *>(duplicate());
287 copy->setflag(status_flags::dynallocated);
288 copy->clearflag(status_flags::hash_calculated);
289 copy->value = f(value);
293 /** Returns order relation between two indices of the same type. The order
294 * must be such that dummy indices lie next to each other. */
295 int idx::compare_same_type(const basic & other) const
297 GINAC_ASSERT(is_a<idx>(other));
298 const idx &o = static_cast<const idx &>(other);
300 int cmpval = value.compare(o.value);
303 return dim.compare(o.dim);
306 bool idx::match_same_type(const basic & other) const
308 GINAC_ASSERT(is_a<idx>(other));
309 const idx &o = static_cast<const idx &>(other);
311 return dim.is_equal(o.dim);
314 int varidx::compare_same_type(const basic & other) const
316 GINAC_ASSERT(is_a<varidx>(other));
317 const varidx &o = static_cast<const varidx &>(other);
319 int cmpval = inherited::compare_same_type(other);
323 // Check variance last so dummy indices will end up next to each other
324 if (covariant != o.covariant)
325 return covariant ? -1 : 1;
330 bool varidx::match_same_type(const basic & other) const
332 GINAC_ASSERT(is_a<varidx>(other));
333 const varidx &o = static_cast<const varidx &>(other);
335 if (covariant != o.covariant)
338 return inherited::match_same_type(other);
341 int spinidx::compare_same_type(const basic & other) const
343 GINAC_ASSERT(is_a<spinidx>(other));
344 const spinidx &o = static_cast<const spinidx &>(other);
346 // Check dottedness first so dummy indices will end up next to each other
347 if (dotted != o.dotted)
348 return dotted ? -1 : 1;
350 int cmpval = inherited::compare_same_type(other);
357 bool spinidx::match_same_type(const basic & other) const
359 GINAC_ASSERT(is_a<spinidx>(other));
360 const spinidx &o = static_cast<const spinidx &>(other);
362 if (dotted != o.dotted)
364 return inherited::match_same_type(other);
367 /** By default, basic::evalf would evaluate the index value but we don't want
368 * a.1 to become a.(1.0). */
369 ex idx::evalf(int level) const
374 ex idx::subs(const lst & ls, const lst & lr, unsigned options) const
376 GINAC_ASSERT(ls.nops() == lr.nops());
378 // First look for index substitutions
379 for (size_t i=0; i<ls.nops(); i++) {
380 if (is_equal(ex_to<basic>(ls.op(i)))) {
382 // Substitution index->index
383 if (is_a<idx>(lr.op(i)))
386 // Otherwise substitute value
387 idx *i_copy = static_cast<idx *>(duplicate());
388 i_copy->value = lr.op(i);
389 i_copy->clearflag(status_flags::hash_calculated);
390 return i_copy->setflag(status_flags::dynallocated);
394 // None, substitute objects in value (not in dimension)
395 const ex &subsed_value = value.subs(ls, lr, options);
396 if (are_ex_trivially_equal(value, subsed_value))
399 idx *i_copy = static_cast<idx *>(duplicate());
400 i_copy->value = subsed_value;
401 i_copy->clearflag(status_flags::hash_calculated);
402 return i_copy->setflag(status_flags::dynallocated);
405 /** Implementation of ex::diff() for an index always returns 0.
408 ex idx::derivative(const symbol & s) const
414 // new virtual functions
417 bool idx::is_dummy_pair_same_type(const basic & other) const
419 const idx &o = static_cast<const idx &>(other);
421 // Only pure symbols form dummy pairs, "2n+1" doesn't
422 if (!is_a<symbol>(value))
425 // Value must be equal, of course
426 if (!value.is_equal(o.value))
429 // Dimensions need not be equal but must be comparable (so we can
430 // determine the minimum dimension of contractions)
431 if (dim.is_equal(o.dim))
434 return (dim < o.dim || dim > o.dim || (is_exactly_a<numeric>(dim) && is_a<symbol>(o.dim)) || (is_a<symbol>(dim) && is_exactly_a<numeric>(o.dim)));
437 bool varidx::is_dummy_pair_same_type(const basic & other) const
439 const varidx &o = static_cast<const varidx &>(other);
441 // Variance must be opposite
442 if (covariant == o.covariant)
445 return inherited::is_dummy_pair_same_type(other);
448 bool spinidx::is_dummy_pair_same_type(const basic & other) const
450 const spinidx &o = static_cast<const spinidx &>(other);
452 // Dottedness must be the same
453 if (dotted != o.dotted)
456 return inherited::is_dummy_pair_same_type(other);
461 // non-virtual functions
464 ex idx::replace_dim(const ex & new_dim) const
466 idx *i_copy = static_cast<idx *>(duplicate());
467 i_copy->dim = new_dim;
468 i_copy->clearflag(status_flags::hash_calculated);
469 return i_copy->setflag(status_flags::dynallocated);
472 ex idx::minimal_dim(const idx & other) const
474 return GiNaC::minimal_dim(dim, other.dim);
477 ex varidx::toggle_variance(void) const
479 varidx *i_copy = static_cast<varidx *>(duplicate());
480 i_copy->covariant = !i_copy->covariant;
481 i_copy->clearflag(status_flags::hash_calculated);
482 return i_copy->setflag(status_flags::dynallocated);
485 ex spinidx::toggle_dot(void) const
487 spinidx *i_copy = static_cast<spinidx *>(duplicate());
488 i_copy->dotted = !i_copy->dotted;
489 i_copy->clearflag(status_flags::hash_calculated);
490 return i_copy->setflag(status_flags::dynallocated);
493 ex spinidx::toggle_variance_dot(void) const
495 spinidx *i_copy = static_cast<spinidx *>(duplicate());
496 i_copy->covariant = !i_copy->covariant;
497 i_copy->dotted = !i_copy->dotted;
498 i_copy->clearflag(status_flags::hash_calculated);
499 return i_copy->setflag(status_flags::dynallocated);
506 bool is_dummy_pair(const idx & i1, const idx & i2)
508 // The indices must be of exactly the same type
509 if (i1.tinfo() != i2.tinfo())
512 // Same type, let the indices decide whether they are paired
513 return i1.is_dummy_pair_same_type(i2);
516 bool is_dummy_pair(const ex & e1, const ex & e2)
518 // The expressions must be indices
519 if (!is_a<idx>(e1) || !is_a<idx>(e2))
522 return is_dummy_pair(ex_to<idx>(e1), ex_to<idx>(e2));
525 void find_free_and_dummy(exvector::const_iterator it, exvector::const_iterator itend, exvector & out_free, exvector & out_dummy)
530 // No indices? Then do nothing
534 // Only one index? Then it is a free one if it's not numeric
535 if (itend - it == 1) {
536 if (ex_to<idx>(*it).is_symbolic())
537 out_free.push_back(*it);
541 // Sort index vector. This will cause dummy indices come to lie next
542 // to each other (because the sort order is defined to guarantee this).
543 exvector v(it, itend);
544 shaker_sort(v.begin(), v.end(), ex_is_less(), ex_swap());
546 // Find dummy pairs and free indices
547 it = v.begin(); itend = v.end();
548 exvector::const_iterator last = it++;
549 while (it != itend) {
550 if (is_dummy_pair(*it, *last)) {
551 out_dummy.push_back(*last);
556 if (!it->is_equal(*last) && ex_to<idx>(*last).is_symbolic())
557 out_free.push_back(*last);
561 if (ex_to<idx>(*last).is_symbolic())
562 out_free.push_back(*last);
565 ex minimal_dim(const ex & dim1, const ex & dim2)
567 if (dim1.is_equal(dim2) || dim1 < dim2 || (is_exactly_a<numeric>(dim1) && is_a<symbol>(dim2)))
569 else if (dim1 > dim2 || (is_a<symbol>(dim1) && is_exactly_a<numeric>(dim2)))
572 std::ostringstream s;
573 s << "minimal_dim(): index dimensions " << dim1 << " and " << dim2 << " cannot be ordered";
574 throw (std::runtime_error(s.str()));