GiNaC  1.8.0
ncmul.cpp
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22 
23 #include "ncmul.h"
24 #include "ex.h"
25 #include "add.h"
26 #include "mul.h"
27 #include "clifford.h"
28 #include "matrix.h"
29 #include "archive.h"
30 #include "indexed.h"
31 #include "utils.h"
32 
33 #include <algorithm>
34 #include <iostream>
35 #include <stdexcept>
36 
37 namespace GiNaC {
38 
41  print_func<print_tree>(&ncmul::do_print_tree).
42  print_func<print_csrc>(&ncmul::do_print_csrc).
43  print_func<print_python_repr>(&ncmul::do_print_csrc))
44 
45 
46 // default constructor
49 
51 {
52 }
53 
55 // other constructors
57 
58 // public
59 
60 ncmul::ncmul(const ex & lh, const ex & rh) : inherited{lh,rh}
61 {
62 }
63 
64 ncmul::ncmul(const ex & f1, const ex & f2, const ex & f3) : inherited{f1,f2,f3}
65 {
66 }
67 
68 ncmul::ncmul(const ex & f1, const ex & f2, const ex & f3,
69  const ex & f4) : inherited{f1,f2,f3,f4}
70 {
71 }
72 
73 ncmul::ncmul(const ex & f1, const ex & f2, const ex & f3,
74  const ex & f4, const ex & f5) : inherited{f1,f2,f3,f4,f5}
75 {
76 }
77 
78 ncmul::ncmul(const ex & f1, const ex & f2, const ex & f3,
79  const ex & f4, const ex & f5, const ex & f6) : inherited{f1,f2,f3,f4,f5,f6}
80 {
81 }
82 
83 ncmul::ncmul(const exvector & v) : inherited(v)
84 {
85 }
86 
87 ncmul::ncmul(exvector && v) : inherited(std::move(v))
88 {
89 }
90 
92 // archiving
94 
95 
97 // functions overriding virtual functions from base classes
99 
100 // public
101 
102 void ncmul::do_print(const print_context & c, unsigned level) const
103 {
104  printseq(c, '(', '*', ')', precedence(), level);
105 }
106 
107 void ncmul::do_print_csrc(const print_context & c, unsigned level) const
108 {
109  c.s << class_name();
110  printseq(c, '(', ',', ')', precedence(), precedence());
111 }
112 
113 bool ncmul::info(unsigned inf) const
114 {
115  return inherited::info(inf);
116 }
117 
118 typedef std::vector<std::size_t> uintvector;
119 
120 ex ncmul::expand(unsigned options) const
121 {
122  // First, expand the children
124  const exvector &expanded_seq = v.empty() ? this->seq : v;
125 
126  // Now, look for all the factors that are sums and remember their
127  // position and number of terms.
128  uintvector positions_of_adds(expanded_seq.size());
129  uintvector number_of_add_operands(expanded_seq.size());
130 
131  size_t number_of_adds = 0;
132  size_t number_of_expanded_terms = 1;
133 
134  size_t current_position = 0;
135  for (auto & it : expanded_seq) {
136  if (is_exactly_a<add>(it)) {
137  positions_of_adds[number_of_adds] = current_position;
138  size_t num_ops = it.nops();
139  number_of_add_operands[number_of_adds] = num_ops;
140  number_of_expanded_terms *= num_ops;
141  number_of_adds++;
142  }
143  ++current_position;
144  }
145 
146  // If there are no sums, we are done
147  if (number_of_adds == 0) {
148  if (!v.empty())
149  return dynallocate<ncmul>(std::move(v)).setflag(options == 0 ? status_flags::expanded : 0);
150  else
151  return *this;
152  }
153 
154  // Now, form all possible products of the terms of the sums with the
155  // remaining factors, and add them together
156  exvector distrseq;
157  distrseq.reserve(number_of_expanded_terms);
158 
159  uintvector k(number_of_adds);
160 
161  /* Rename indices in the static members of the product */
162  exvector expanded_seq_mod;
163  size_t j = 0;
164  exvector va;
165 
166  for (size_t i=0; i<expanded_seq.size(); i++) {
167  if (i == positions_of_adds[j]) {
168  expanded_seq_mod.push_back(_ex1);
169  j++;
170  } else {
171  expanded_seq_mod.push_back(rename_dummy_indices_uniquely(va, expanded_seq[i], true));
172  }
173  }
174 
175  while (true) {
176  exvector term = expanded_seq_mod;
177  for (size_t i=0; i<number_of_adds; i++) {
178  term[positions_of_adds[i]] = rename_dummy_indices_uniquely(va, expanded_seq[positions_of_adds[i]].op(k[i]), true);
179  }
180 
181  distrseq.push_back(dynallocate<ncmul>(std::move(term)).setflag(options == 0 ? status_flags::expanded : 0));
182 
183  // increment k[]
184  int l = number_of_adds-1;
185  while ((l>=0) && ((++k[l]) >= number_of_add_operands[l])) {
186  k[l] = 0;
187  l--;
188  }
189  if (l<0)
190  break;
191  }
192 
193  return dynallocate<add>(distrseq).setflag(options == 0 ? status_flags::expanded : 0);
194 }
195 
196 int ncmul::degree(const ex & s) const
197 {
198  if (is_equal(ex_to<basic>(s)))
199  return 1;
200 
201  // Sum up degrees of factors
202  int deg_sum = 0;
203  for (auto & i : seq)
204  deg_sum += i.degree(s);
205  return deg_sum;
206 }
207 
208 int ncmul::ldegree(const ex & s) const
209 {
210  if (is_equal(ex_to<basic>(s)))
211  return 1;
212 
213  // Sum up degrees of factors
214  int deg_sum = 0;
215  for (auto & i : seq)
216  deg_sum += i.degree(s);
217  return deg_sum;
218 }
219 
220 ex ncmul::coeff(const ex & s, int n) const
221 {
222  if (is_equal(ex_to<basic>(s)))
223  return n==1 ? _ex1 : _ex0;
224 
225  exvector coeffseq;
226  coeffseq.reserve(seq.size());
227 
228  if (n == 0) {
229  // product of individual coeffs
230  // if a non-zero power of s is found, the resulting product will be 0
231  for (auto & it : seq)
232  coeffseq.push_back(it.coeff(s,n));
233  return dynallocate<ncmul>(std::move(coeffseq));
234  }
235 
236  bool coeff_found = false;
237  for (auto & i : seq) {
238  ex c = i.coeff(s,n);
239  if (c.is_zero()) {
240  coeffseq.push_back(i);
241  } else {
242  coeffseq.push_back(c);
243  coeff_found = true;
244  }
245  }
246 
247  if (coeff_found)
248  return dynallocate<ncmul>(std::move(coeffseq));
249 
250  return _ex0;
251 }
252 
253 size_t ncmul::count_factors(const ex & e) const
254 {
255  if ((is_exactly_a<mul>(e)&&(e.return_type()!=return_types::commutative))||
256  (is_exactly_a<ncmul>(e))) {
257  size_t factors=0;
258  for (size_t i=0; i<e.nops(); i++)
259  factors += count_factors(e.op(i));
260 
261  return factors;
262  }
263  return 1;
264 }
265 
266 void ncmul::append_factors(exvector & v, const ex & e) const
267 {
268  if ((is_exactly_a<mul>(e)&&(e.return_type()!=return_types::commutative))||
269  (is_exactly_a<ncmul>(e))) {
270  for (size_t i=0; i<e.nops(); i++)
271  append_factors(v, e.op(i));
272  } else
273  v.push_back(e);
274 }
275 
276 typedef std::vector<unsigned> unsignedvector;
277 typedef std::vector<exvector> exvectorvector;
278 
290 {
291  // The following additional rule would be nice, but produces a recursion,
292  // which must be trapped by introducing a flag that the sub-ncmuls()
293  // are already evaluated (maybe later...)
294  // ncmul(x1,x2,...,X,y1,y2,...) ->
295  // ncmul(ncmul(x1,x2,...),X,ncmul(y1,y2,...)
296  // (X noncommutative_composite)
297 
299  return *this;
300  }
301 
302  // ncmul(...,*(x1,x2),...,ncmul(x3,x4),...) ->
303  // ncmul(...,x1,x2,...,x3,x4,...) (associativity)
304  size_t factors = 0;
305  for (auto & it : seq)
306  factors += count_factors(it);
307 
308  exvector assocseq;
309  assocseq.reserve(factors);
310  make_flat_inserter mf(seq, true);
311  for (auto & it : seq) {
312  ex factor = mf.handle_factor(it, 1);
313  append_factors(assocseq, factor);
314  }
315 
316  // ncmul(x) -> x
317  if (assocseq.size()==1) return *(seq.begin());
318 
319  // ncmul() -> 1
320  if (assocseq.empty()) return _ex1;
321 
322  // determine return types
323  unsignedvector rettypes(assocseq.size());
324  size_t i = 0;
325  size_t count_commutative=0;
326  size_t count_noncommutative=0;
327  size_t count_noncommutative_composite=0;
328  for (auto & it : assocseq) {
329  rettypes[i] = it.return_type();
330  switch (rettypes[i]) {
332  count_commutative++;
333  break;
335  count_noncommutative++;
336  break;
338  count_noncommutative_composite++;
339  break;
340  default:
341  throw(std::logic_error("ncmul::eval(): invalid return type"));
342  }
343  ++i;
344  }
345  GINAC_ASSERT(count_commutative+count_noncommutative+count_noncommutative_composite==assocseq.size());
346 
347  // ncmul(...,c1,...,c2,...) ->
348  // *(c1,c2,ncmul(...)) (pull out commutative elements)
349  if (count_commutative!=0) {
350  exvector commutativeseq;
351  commutativeseq.reserve(count_commutative+1);
352  exvector noncommutativeseq;
353  noncommutativeseq.reserve(assocseq.size()-count_commutative);
354  size_t num = assocseq.size();
355  for (size_t i=0; i<num; ++i) {
356  if (rettypes[i]==return_types::commutative)
357  commutativeseq.push_back(assocseq[i]);
358  else
359  noncommutativeseq.push_back(assocseq[i]);
360  }
361  commutativeseq.push_back(dynallocate<ncmul>(std::move(noncommutativeseq)));
362  return dynallocate<mul>(std::move(commutativeseq));
363  }
364 
365  // ncmul(x1,y1,x2,y2) -> *(ncmul(x1,x2),ncmul(y1,y2))
366  // (collect elements of same type)
367 
368  if (count_noncommutative_composite==0) {
369  // there are neither commutative nor noncommutative_composite
370  // elements in assocseq
371  GINAC_ASSERT(count_commutative==0);
372 
373  size_t assoc_num = assocseq.size();
374  exvectorvector evv;
375  std::vector<return_type_t> rttinfos;
376  evv.reserve(assoc_num);
377  rttinfos.reserve(assoc_num);
378 
379  for (auto & it : assocseq) {
380  return_type_t ti = it.return_type_tinfo();
381  size_t rtt_num = rttinfos.size();
382  // search type in vector of known types
383  for (i=0; i<rtt_num; ++i) {
384  if(ti == rttinfos[i]) {
385  evv[i].push_back(it);
386  break;
387  }
388  }
389  if (i >= rtt_num) {
390  // new type
391  rttinfos.push_back(ti);
392  evv.push_back(exvector());
393  (evv.end()-1)->reserve(assoc_num);
394  (evv.end()-1)->push_back(it);
395  }
396  }
397 
398  size_t evv_num = evv.size();
399 #ifdef DO_GINAC_ASSERT
400  GINAC_ASSERT(evv_num == rttinfos.size());
401  GINAC_ASSERT(evv_num > 0);
402  size_t s=0;
403  for (i=0; i<evv_num; ++i)
404  s += evv[i].size();
405  GINAC_ASSERT(s == assoc_num);
406 #endif // def DO_GINAC_ASSERT
407 
408  // if all elements are of same type, simplify the string
409  if (evv_num == 1) {
410  return evv[0][0].eval_ncmul(evv[0]);
411  }
412 
413  exvector splitseq;
414  splitseq.reserve(evv_num);
415  for (i=0; i<evv_num; ++i)
416  splitseq.push_back(dynallocate<ncmul>(evv[i]));
417 
418  return dynallocate<mul>(splitseq);
419  }
420 
421  return dynallocate<ncmul>(assocseq).setflag(status_flags::evaluated);
422 }
423 
425 {
426  // Evaluate children first
427  exvector s;
428  s.reserve(seq.size());
429  for (auto & it : seq)
430  s.push_back(it.evalm());
431 
432  // If there are only matrices, simply multiply them
433  auto it = s.begin(), itend = s.end();
434  if (is_a<matrix>(*it)) {
435  matrix prod(ex_to<matrix>(*it));
436  it++;
437  while (it != itend) {
438  if (!is_a<matrix>(*it))
439  goto no_matrix;
440  prod = prod.mul(ex_to<matrix>(*it));
441  it++;
442  }
443  return prod;
444  }
445 
446 no_matrix:
447  return dynallocate<ncmul>(std::move(s));
448 }
449 
451 {
452  return dynallocate<ncmul>(v);
453 }
454 
456 {
457  return dynallocate<ncmul>(std::move(v));
458 }
459 
461 {
463  return exprseq::conjugate();
464  }
465 
467  return exprseq::conjugate();
468  }
469 
470  exvector ev;
471  ev.reserve(nops());
472  for (auto i=end(); i!=begin();) {
473  --i;
474  ev.push_back(i->conjugate());
475  }
476  return dynallocate<ncmul>(std::move(ev));
477 }
478 
480 {
481  return basic::real_part();
482 }
483 
485 {
486  return basic::imag_part();
487 }
488 
489 // protected
490 
494 ex ncmul::derivative(const symbol & s) const
495 {
496  size_t num = seq.size();
497  exvector addseq;
498  addseq.reserve(num);
499 
500  // D(a*b*c) = D(a)*b*c + a*D(b)*c + a*b*D(c)
501  exvector ncmulseq = seq;
502  for (size_t i=0; i<num; ++i) {
503  ex e = seq[i].diff(s);
504  e.swap(ncmulseq[i]);
505  addseq.push_back(dynallocate<ncmul>(ncmulseq));
506  e.swap(ncmulseq[i]);
507  }
508  return dynallocate<add>(addseq);
509 }
510 
511 int ncmul::compare_same_type(const basic & other) const
512 {
513  return inherited::compare_same_type(other);
514 }
515 
516 unsigned ncmul::return_type() const
517 {
518  if (seq.empty())
520 
521  bool all_commutative = true;
522  exvector::const_iterator noncommutative_element; // point to first found nc element
523 
524  auto i = seq.begin(), end = seq.end();
525  while (i != end) {
526  unsigned rt = i->return_type();
528  return rt; // one ncc -> mul also ncc
529  if ((rt == return_types::noncommutative) && (all_commutative)) {
530  // first nc element found, remember position
531  noncommutative_element = i;
532  all_commutative = false;
533  }
534  if ((rt == return_types::noncommutative) && (!all_commutative)) {
535  // another nc element found, compare type_infos
536  if(noncommutative_element->return_type_tinfo() != i->return_type_tinfo())
538  }
539  ++i;
540  }
541  // all factors checked
542  GINAC_ASSERT(!all_commutative); // not all factors should commutate, because this is a ncmul();
543  return all_commutative ? return_types::commutative : return_types::noncommutative;
544 }
545 
547 {
548  if (seq.empty())
549  return make_return_type_t<ncmul>();
550 
551  // return type_info of first noncommutative element
552  for (auto & i : seq)
553  if (i.return_type() == return_types::noncommutative)
554  return i.return_type_tinfo();
555 
556  // no noncommutative element found, should not happen
557  return make_return_type_t<ncmul>();
558 }
559 
561 // new virtual functions which can be overridden by derived classes
563 
564 // none
565 
567 // non-virtual functions in this class
569 
571 {
572  auto cit = this->seq.begin(), end = this->seq.end();
573  while (cit != end) {
574  const ex & expanded_ex = cit->expand(options);
575  if (!are_ex_trivially_equal(*cit, expanded_ex)) {
576 
577  // copy first part of seq which hasn't changed
578  exvector s(this->seq.begin(), cit);
579  s.reserve(this->seq.size());
580 
581  // insert changed element
582  s.push_back(expanded_ex);
583  ++cit;
584 
585  // copy rest
586  while (cit != end) {
587  s.push_back(cit->expand(options));
588  ++cit;
589  }
590 
591  return s;
592  }
593 
594  ++cit;
595  }
596 
597  return exvector(); // nothing has changed
598 }
599 
601 {
602  return seq;
603 }
604 
606 // friend functions
608 
610 {
611  return dynallocate<ncmul>(v);
612 }
613 
615 {
616  if (v.empty())
617  return _ex1;
618  else if (v.size() == 1)
619  return v[0];
620  else
621  return dynallocate<ncmul>(v).setflag(status_flags::evaluated);
622 }
623 
624 GINAC_BIND_UNARCHIVER(ncmul);
625 
626 } // namespace GiNaC
bool is_clifford_tinfo(const return_type_t &ti)
Check whether a given return_type_t object (as returned by return_type_tinfo() is that of a clifford ...
Definition: clifford.h:194
Non-commutative product of expressions.
Definition: ncmul.h:32
Interface to GiNaC&#39;s indexed expressions.
ex op(size_t i) const override
Return operand/member at position i.
Definition: container.h:295
ncmul(const ex &lh, const ex &rh)
Definition: ncmul.cpp:60
bool info(unsigned inf) const override
Information about the object.
Definition: ncmul.cpp:113
Interface to GiNaC&#39;s clifford algebra (Dirac gamma) objects.
const basic & setflag(unsigned f) const
Set some status_flags.
Definition: basic.h:288
ex expand(unsigned options=0) const
Definition: ex.cpp:73
Definition: add.cpp:38
upvec factors
Definition: factor.cpp:1461
Definition: ex.h:972
virtual void printseq(const print_context &c, char openbracket, char delim, char closebracket, unsigned this_precedence, unsigned upper_precedence=0) const
Print sequence of contained elements.
Definition: container.h:451
Archiving of GiNaC expressions.
Interface to GiNaC&#39;s sums of expressions.
This class is the ABC (abstract base class) of GiNaC&#39;s class hierarchy.
Definition: basic.h:104
size_t nops() const
Definition: ex.h:135
const ex _ex0
Definition: utils.cpp:177
bool are_ex_trivially_equal(const ex &e1, const ex &e2)
Compare two objects of class quickly without doing a deep tree traversal.
Definition: ex.h:684
return_type_t return_type_tinfo() const override
Definition: ncmul.cpp:546
unsigned return_type() const override
Definition: ncmul.cpp:516
std::vector< unsigned > unsignedvector
Definition: ncmul.cpp:276
size_t count_factors(const ex &e) const
Definition: ncmul.cpp:253
virtual ex imag_part() const
Definition: basic.cpp:681
Interface to GiNaC&#39;s products of expressions.
int ldegree(const ex &s) const override
Return degree of lowest power in object s.
Definition: ncmul.cpp:208
ex op(size_t i) const
Definition: ex.h:136
Interface to several small and furry utilities needed within GiNaC but not of any interest to the use...
const ex _ex1
Definition: utils.cpp:193
void do_print(const print_context &c, unsigned level) const
Definition: ncmul.cpp:102
const_iterator begin() const noexcept
Definition: ex.h:647
Class to handle the renaming of dummy indices.
Definition: expairseq.h:135
print_func< print_context >(&varidx::do_print). print_func< print_latex >(&varidx
Definition: idx.cpp:45
vector< int > k
Definition: factor.cpp:1466
unsigned options
Definition: factor.cpp:2480
size_t nops() const override
Number of operands/members.
Definition: container.h:118
std::vector< std::size_t > uintvector
Definition: ncmul.cpp:118
#define GINAC_ASSERT(X)
Assertion macro for checking invariances.
Definition: assertion.h:33
ex hold_ncmul(const exvector &v)
Definition: ncmul.cpp:614
void append_factors(exvector &v, const ex &e) const
Definition: ncmul.cpp:266
matrix mul(const matrix &other) const
Product of matrices.
Definition: matrix.cpp:589
exvector expandchildren(unsigned options) const
Definition: ncmul.cpp:570
GINAC_IMPLEMENT_REGISTERED_CLASS_OPT(add, expairseq, print_func< print_context >(&add::do_print). print_func< print_latex >(&add::do_print_latex). print_func< print_csrc >(&add::do_print_csrc). print_func< print_tree >(&add::do_print_tree). print_func< print_python_repr >(&add::do_print_python_repr)) add
Definition: add.cpp:40
To distinguish between different kinds of non-commutative objects.
Definition: registrar.h:43
const_iterator end() const
Definition: container.h:240
Interface to symbolic matrices.
std::vector< ex > exvector
Definition: basic.h:46
void do_print_tree(const print_tree &c, unsigned level) const
Definition: container.h:267
ex real_part() const override
Definition: ncmul.cpp:479
size_t n
Definition: factor.cpp:1463
Interface to GiNaC&#39;s light-weight expression handles.
ex imag_part() const override
Definition: ncmul.cpp:484
ex factor(const ex &poly, unsigned options)
Interface function to the outside world.
Definition: factor.cpp:2581
Base class for print_contexts.
Definition: print.h:102
ex coeff(const ex &s, int n=1) const override
Return coefficient of degree n in object s.
Definition: ncmul.cpp:220
const_iterator begin() const
Definition: container.h:239
Lightweight wrapper for GiNaC&#39;s symbolic objects.
Definition: ex.h:72
const exvector & get_factors() const
Definition: ncmul.cpp:600
ex eval() const override
Perform automatic term rewriting rules in this class.
Definition: ncmul.cpp:289
Interface to GiNaC&#39;s non-commutative products of expressions.
lst rename_dummy_indices_uniquely(const exvector &va, const exvector &vb)
Similar to above, where va and vb are the same and the return value is a list of two lists for substi...
Definition: indexed.cpp:1460
ex expand(unsigned options=0) const override
Expand expression, i.e.
Definition: ncmul.cpp:120
ex thiscontainer(const exvector &v) const override
Definition: ncmul.cpp:450
ex derivative(const symbol &s) const override
Implementation of ex::diff() for a non-commutative product.
Definition: ncmul.cpp:494
ex evalm() const override
Evaluate sums, products and integer powers of matrices.
Definition: ncmul.cpp:424
bool is_equal(const basic &other) const
Test for syntactic equality.
Definition: basic.cpp:863
Basic CAS symbol.
Definition: symbol.h:38
virtual int compare_same_type(const basic &other) const
Returns order relation between two objects of same type.
Definition: basic.cpp:719
unsigned return_type() const
Definition: ex.h:230
ex reeval_ncmul(const exvector &v)
Definition: ncmul.cpp:609
Wrapper template for making GiNaC classes out of STL containers.
Definition: container.h:73
.expand(0) has already done its job (other expand() options ignore this flag)
Definition: flags.h:204
Symbolic matrices.
Definition: matrix.h:37
virtual ex real_part() const
Definition: basic.cpp:676
void do_print_csrc(const print_context &c, unsigned level) const
Definition: ncmul.cpp:107
unsigned precedence() const override
Return relative operator precedence (for parenthezing output).
Definition: ncmul.h:57
ex handle_factor(const ex &x, const ex &coeff)
Definition: expairseq.h:153
std::vector< exvector > exvectorvector
Definition: ncmul.cpp:277
int degree(const ex &s) const override
Return degree of highest power in object s.
Definition: ncmul.cpp:196
void reserve(size_t)
Definition: container.h:54
ex conjugate() const override
Definition: container.h:147
size_t c
Definition: factor.cpp:770
ex conjugate() const override
Definition: ncmul.cpp:460
.eval() has already done its job
Definition: flags.h:203
void swap(ex &other) noexcept
Efficiently swap the contents of two expressions.
Definition: ex.h:104
unsigned flags
of type status_flags
Definition: basic.h:302
GINAC_BIND_UNARCHIVER(add)

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