ginac/add.cpp

   1 /** @file add.cpp
   2  *
   3  *  Implementation of GiNaC's sums of expressions. */
   4
   5 /*
   6  *  GiNaC Copyright (C) 1999-2001 Johannes Gutenberg University Mainz, Germany
   7  *
   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.
  12  *
  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.
  17  *
  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
  21  */
  22
  23 #include <iostream>
  24 #include <stdexcept>
  25
  26 #include "add.h"
  27 #include "mul.h"
  28 #include "archive.h"
  29 #include "debugmsg.h"
  30 #include "utils.h"
  31
  32 namespace GiNaC {
  33
  34 GINAC_IMPLEMENT_REGISTERED_CLASS(add, expairseq)
  35
  36 //////////
  37 // default constructor, destructor, copy constructor assignment operator and helpers
  38 //////////
  39
  40 add::add()
  41 {
  42         debugmsg("add default constructor",LOGLEVEL_CONSTRUCT);
  43         tinfo_key = TINFO_add;
  44 }
  45
  46 DEFAULT_COPY(add)
  47 DEFAULT_DESTROY(add)
  48
  49 //////////
  50 // other constructors
  51 //////////
  52
  53 // public
  54
  55 add::add(const ex & lh, const ex & rh)
  56 {
  57         debugmsg("add constructor from ex,ex",LOGLEVEL_CONSTRUCT);
  58         tinfo_key = TINFO_add;
  59         overall_coeff = _ex0();
  60         construct_from_2_ex(lh,rh);
  61         GINAC_ASSERT(is_canonical());
  62 }
  63
  64 add::add(const exvector & v)
  65 {
  66         debugmsg("add constructor from exvector",LOGLEVEL_CONSTRUCT);
  67         tinfo_key = TINFO_add;
  68         overall_coeff = _ex0();
  69         construct_from_exvector(v);
  70         GINAC_ASSERT(is_canonical());
  71 }
  72
  73 add::add(const epvector & v)
  74 {
  75         debugmsg("add constructor from epvector",LOGLEVEL_CONSTRUCT);
  76         tinfo_key = TINFO_add;
  77         overall_coeff = _ex0();
  78         construct_from_epvector(v);
  79         GINAC_ASSERT(is_canonical());
  80 }
  81
  82 add::add(const epvector & v, const ex & oc)
  83 {
  84         debugmsg("add constructor from epvector,ex",LOGLEVEL_CONSTRUCT);
  85         tinfo_key = TINFO_add;
  86         overall_coeff = oc;
  87         construct_from_epvector(v);
  88         GINAC_ASSERT(is_canonical());
  89 }
  90
  91 add::add(epvector * vp, const ex & oc)
  92 {
  93         debugmsg("add constructor from epvector *,ex",LOGLEVEL_CONSTRUCT);
  94         tinfo_key = TINFO_add;
  95         GINAC_ASSERT(vp!=0);
  96         overall_coeff = oc;
  97         construct_from_epvector(*vp);
  98         delete vp;
  99         GINAC_ASSERT(is_canonical());
 100 }
 101
 102 //////////
 103 // archiving
 104 //////////
 105
 106 DEFAULT_ARCHIVING(add)
 107
 108 //////////
 109 // functions overriding virtual functions from bases classes
 110 //////////
 111
 112 // public
 113
 114 void add::print(const print_context & c, unsigned level) const
 115 {
 116         debugmsg("add print", LOGLEVEL_PRINT);
 117
 118         if (is_of_type(c, print_tree)) {
 119
 120                 inherited::print(c, level);
 121
 122         } else if (is_of_type(c, print_csrc)) {
 123
 124                 if (precedence <= level)
 125                         c.s << "(";
 126
 127                 // Print arguments, separated by "+"
 128                 epvector::const_iterator it = seq.begin(), itend = seq.end();
 129                 while (it != itend) {
 130
 131                         // If the coefficient is -1, it is replaced by a single minus sign
 132                         if (it->coeff.compare(_num1()) == 0) {
 133                                 it->rest.bp->print(c, precedence);
 134                         } else if (it->coeff.compare(_num_1()) == 0) {
 135                                 c.s << "-";
 136                                 it->rest.bp->print(c, precedence);
 137                         } else if (ex_to_numeric(it->coeff).numer().compare(_num1()) == 0) {
 138                                 it->rest.bp->print(c, precedence);
 139                                 c.s << "/";
 140                                 ex_to_numeric(it->coeff).denom().print(c, precedence);
 141                         } else if (ex_to_numeric(it->coeff).numer().compare(_num_1()) == 0) {
 142                                 c.s << "-";
 143                                 it->rest.bp->print(c, precedence);
 144                                 c.s << "/";
 145                                 ex_to_numeric(it->coeff).denom().print(c, precedence);
 146                         } else {
 147                                 it->coeff.bp->print(c, precedence);
 148                                 c.s << "*";
 149                                 it->rest.bp->print(c, precedence);
 150                         }
 151
 152                         // Separator is "+", except if the following expression would have a leading minus sign
 153                         it++;
 154                         if (it != itend && !(it->coeff.compare(_num0()) < 0 || (it->coeff.compare(_num1()) == 0 && is_ex_exactly_of_type(it->rest, numeric) && it->rest.compare(_num0()) < 0)))
 155                                 c.s << "+";
 156                 }
 157
 158                 if (!overall_coeff.is_zero()) {
 159                         if (overall_coeff.info(info_flags::positive))
 160                                 c.s << '+';
 161                         overall_coeff.bp->print(c, precedence);
 162                 }
 163
 164                 if (precedence <= level)
 165                         c.s << ")";
 166
 167         } else {
 168
 169                 if (precedence <= level)
 170                         c.s << "(";
 171
 172                 numeric coeff;
 173                 bool first = true;
 174
 175                 // First print the overall numeric coefficient, if present
 176                 if (!overall_coeff.is_zero()) {
 177                         overall_coeff.print(c, precedence);
 178                         first = false;
 179                 }
 180
 181                 // Then proceed with the remaining factors
 182                 epvector::const_iterator it = seq.begin(), itend = seq.end();
 183                 while (it != itend) {
 184                         coeff = ex_to_numeric(it->coeff);
 185                         if (!first) {
 186                                 if (coeff.csgn() == -1) c.s << '-'; else c.s << '+';
 187                         } else {
 188                                 if (coeff.csgn() == -1) c.s << '-';
 189                                 first = false;
 190                         }
 191                         if (!coeff.is_equal(_num1()) &&
 192                             !coeff.is_equal(_num_1())) {
 193                                 if (coeff.is_rational()) {
 194                                         if (coeff.is_negative())
 195                                                 (-coeff).print(c);
 196                                         else
 197                                                 coeff.print(c);
 198                                 } else {
 199                                         if (coeff.csgn() == -1)
 200                                                 (-coeff).print(c, precedence);
 201                                         else
 202                                                 coeff.print(c, precedence);
 203                                 }
 204                                 c.s << '*';
 205                         }
 206                         it->rest.print(c, precedence);
 207                         it++;
 208                 }
 209
 210                 if (precedence <= level)
 211                         c.s << ")";
 212         }
 213 }
 214
 215 bool add::info(unsigned inf) const
 216 {
 217         switch (inf) {
 218                 case info_flags::polynomial:
 219                 case info_flags::integer_polynomial:
 220                 case info_flags::cinteger_polynomial:
 221                 case info_flags::rational_polynomial:
 222                 case info_flags::crational_polynomial:
 223                 case info_flags::rational_function: {
 224                         for (epvector::const_iterator i=seq.begin(); i!=seq.end(); ++i) {
 225                                 if (!(recombine_pair_to_ex(*i).info(inf)))
 226                                         return false;
 227                         }
 228                         return overall_coeff.info(inf);
 229                 }
 230                 case info_flags::algebraic: {
 231                         for (epvector::const_iterator i=seq.begin(); i!=seq.end(); ++i) {
 232                                 if ((recombine_pair_to_ex(*i).info(inf)))
 233                                         return true;
 234                         }
 235                         return false;
 236                 }
 237         }
 238         return inherited::info(inf);
 239 }
 240
 241 int add::degree(const ex & s) const
 242 {
 243         int deg = INT_MIN;
 244         if (!overall_coeff.is_equal(_ex0()))
 245                 deg = 0;
 246
 247         int cur_deg;
 248         for (epvector::const_iterator cit=seq.begin(); cit!=seq.end(); ++cit) {
 249                 cur_deg = (*cit).rest.degree(s);
 250                 if (cur_deg>deg)
 251                         deg = cur_deg;
 252         }
 253         return deg;
 254 }
 255
 256 int add::ldegree(const ex & s) const
 257 {
 258         int deg = INT_MAX;
 259         if (!overall_coeff.is_equal(_ex0()))
 260                 deg = 0;
 261
 262         int cur_deg;
 263         for (epvector::const_iterator cit=seq.begin(); cit!=seq.end(); ++cit) {
 264                 cur_deg = (*cit).rest.ldegree(s);
 265                 if (cur_deg<deg) deg=cur_deg;
 266         }
 267         return deg;
 268 }
 269
 270 ex add::coeff(const ex & s, int n) const
 271 {
 272         epvector coeffseq;
 273         coeffseq.reserve(seq.size());
 274
 275         epvector::const_iterator it=seq.begin();
 276         while (it!=seq.end()) {
 277                 coeffseq.push_back(combine_ex_with_coeff_to_pair((*it).rest.coeff(s,n),
 278                                                                  (*it).coeff));
 279                 ++it;
 280         }
 281         if (n==0) {
 282                 return (new add(coeffseq,overall_coeff))->setflag(status_flags::dynallocated);
 283         }
 284         return (new add(coeffseq))->setflag(status_flags::dynallocated);
 285 }
 286
 287 ex add::eval(int level) const
 288 {
 289         // simplifications: +(;c) -> c
 290         //                  +(x;1) -> x
 291
 292         debugmsg("add eval",LOGLEVEL_MEMBER_FUNCTION);
 293
 294         epvector * evaled_seqp = evalchildren(level);
 295         if (evaled_seqp!=0) {
 296                 // do more evaluation later
 297                 return (new add(evaled_seqp,overall_coeff))->
 298                        setflag(status_flags::dynallocated);
 299         }
 300
 301 #ifdef DO_GINAC_ASSERT
 302         for (epvector::const_iterator cit=seq.begin(); cit!=seq.end(); ++cit) {
 303                 GINAC_ASSERT(!is_ex_exactly_of_type((*cit).rest,add));
 304                 if (is_ex_exactly_of_type((*cit).rest,numeric))
 305                         dbgprint();
 306                 GINAC_ASSERT(!is_ex_exactly_of_type((*cit).rest,numeric));
 307         }
 308 #endif // def DO_GINAC_ASSERT
 309
 310         if (flags & status_flags::evaluated) {
 311                 GINAC_ASSERT(seq.size()>0);
 312                 GINAC_ASSERT(seq.size()>1 || !overall_coeff.is_zero());
 313                 return *this;
 314         }
 315
 316         int seq_size = seq.size();
 317         if (seq_size==0) {
 318                 // +(;c) -> c
 319                 return overall_coeff;
 320         } else if ((seq_size==1) && overall_coeff.is_equal(_ex0())) {
 321                 // +(x;0) -> x
 322                 return recombine_pair_to_ex(*(seq.begin()));
 323         }
 324         return this->hold();
 325 }
 326
 327 ex add::simplify_ncmul(const exvector & v) const
 328 {
 329         if (seq.size()==0) {
 330                 return inherited::simplify_ncmul(v);
 331         }
 332         return (*seq.begin()).rest.simplify_ncmul(v);
 333 }
 334
 335 // protected
 336
 337 /** Implementation of ex::diff() for a sum. It differentiates each term.
 338  *  @see ex::diff */
 339 ex add::derivative(const symbol & s) const
 340 {
 341         // D(a+b+c)=D(a)+D(b)+D(c)
 342         return (new add(diffchildren(s)))->setflag(status_flags::dynallocated);
 343 }
 344
 345 int add::compare_same_type(const basic & other) const
 346 {
 347         return inherited::compare_same_type(other);
 348 }
 349
 350 bool add::is_equal_same_type(const basic & other) const
 351 {
 352         return inherited::is_equal_same_type(other);
 353 }
 354
 355 unsigned add::return_type(void) const
 356 {
 357         if (seq.size()==0) {
 358                 return return_types::commutative;
 359         }
 360         return (*seq.begin()).rest.return_type();
 361 }
 362
 363 unsigned add::return_type_tinfo(void) const
 364 {
 365         if (seq.size()==0) {
 366                 return tinfo_key;
 367         }
 368         return (*seq.begin()).rest.return_type_tinfo();
 369 }
 370
 371 ex add::thisexpairseq(const epvector & v, const ex & oc) const
 372 {
 373         return (new add(v,oc))->setflag(status_flags::dynallocated);
 374 }
 375
 376 ex add::thisexpairseq(epvector * vp, const ex & oc) const
 377 {
 378         return (new add(vp,oc))->setflag(status_flags::dynallocated);
 379 }
 380
 381 expair add::split_ex_to_pair(const ex & e) const
 382 {
 383         if (is_ex_exactly_of_type(e,mul)) {
 384                 const mul &mulref = ex_to_mul(e);
 385                 ex numfactor = mulref.overall_coeff;
 386                 mul *mulcopyp = new mul(mulref);
 387                 mulcopyp->overall_coeff = _ex1();
 388                 mulcopyp->clearflag(status_flags::evaluated);
 389                 mulcopyp->clearflag(status_flags::hash_calculated);
 390                 mulcopyp->setflag(status_flags::dynallocated);
 391                 return expair(*mulcopyp,numfactor);
 392         }
 393         return expair(e,_ex1());
 394 }
 395
 396 expair add::combine_ex_with_coeff_to_pair(const ex & e,
 397                                                                                   const ex & c) const
 398 {
 399         GINAC_ASSERT(is_ex_exactly_of_type(c, numeric));
 400         if (is_ex_exactly_of_type(e, mul)) {
 401                 const mul &mulref = ex_to_mul(e);
 402                 ex numfactor = mulref.overall_coeff;
 403                 mul *mulcopyp = new mul(mulref);
 404                 mulcopyp->overall_coeff = _ex1();
 405                 mulcopyp->clearflag(status_flags::evaluated);
 406                 mulcopyp->clearflag(status_flags::hash_calculated);
 407                 mulcopyp->setflag(status_flags::dynallocated);
 408                 if (are_ex_trivially_equal(c, _ex1()))
 409                         return expair(*mulcopyp, numfactor);
 410                 else if (are_ex_trivially_equal(numfactor, _ex1()))
 411                         return expair(*mulcopyp, c);
 412                 else
 413                         return expair(*mulcopyp, ex_to_numeric(numfactor).mul_dyn(ex_to_numeric(c)));
 414         } else if (is_ex_exactly_of_type(e, numeric)) {
 415                 if (are_ex_trivially_equal(c, _ex1()))
 416                         return expair(e, _ex1());
 417                 return expair(ex_to_numeric(e).mul_dyn(ex_to_numeric(c)), _ex1());
 418         }
 419         return expair(e, c);
 420 }
 421
 422 expair add::combine_pair_with_coeff_to_pair(const expair & p,
 423                                                                                         const ex & c) const
 424 {
 425         GINAC_ASSERT(is_ex_exactly_of_type(p.coeff,numeric));
 426         GINAC_ASSERT(is_ex_exactly_of_type(c,numeric));
 427
 428         if (is_ex_exactly_of_type(p.rest,numeric)) {
 429                 GINAC_ASSERT(ex_to_numeric(p.coeff).is_equal(_num1())); // should be normalized
 430                 return expair(ex_to_numeric(p.rest).mul_dyn(ex_to_numeric(c)),_ex1());
 431         }
 432
 433         return expair(p.rest,ex_to_numeric(p.coeff).mul_dyn(ex_to_numeric(c)));
 434 }
 435
 436 ex add::recombine_pair_to_ex(const expair & p) const
 437 {
 438         if (ex_to_numeric(p.coeff).is_equal(_num1()))
 439                 return p.rest;
 440         else
 441                 return p.rest*p.coeff;
 442 }
 443
 444 ex add::expand(unsigned options) const
 445 {
 446         if (flags & status_flags::expanded)
 447                 return *this;
 448
 449         epvector * vp = expandchildren(options);
 450         if (vp==0) {
 451                 // the terms have not changed, so it is safe to declare this expanded
 452                 setflag(status_flags::expanded);
 453                 return *this;
 454         }
 455
 456         return (new add(vp,overall_coeff))->setflag(status_flags::expanded | status_flags::dynallocated);
 457 }
 458
 459 //////////
 460 // static member variables
 461 //////////
 462
 463 // protected
 464
 465 unsigned add::precedence = 40;
 466
 467 } // namespace GiNaC