Changeset 40227a in git for factory/libfac/charset/alg_factor.cc
 Timestamp:
 Mar 7, 2014, 2:01:40 PM (10 years ago)
 Branches:
 (u'spielwiese', 'e7cc1ebecb61be8b9ca6c18016352af89940b21a')
 Children:
 36914e05c0ccbede3cb5e25cf2aec8fb52db5905
 Parents:
 e0fbbebbddf89f036945fdc00a1659b1841bc7aa
 gitauthor:
 Martin Lee <martinlee84@web.de>20140307 14:01:40+01:00
 gitcommitter:
 Hans Schoenemann <hannes@mathematik.unikl.de>20140317 18:31:54+01:00
 File:

 1 edited
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factory/libfac/charset/alg_factor.cc
re0fbbeb r40227a 375 375 } 376 376 while ( 1 ); 377 } 378 379 380 /// pseudo division of f and g wrt. x s.t. multiplier*f=q*g+r 381 /// but only if the leading coefficient of g is of level lower than coeffLevel 382 void 383 psqr (const CanonicalForm & f, const CanonicalForm & g, CanonicalForm & q, 384 CanonicalForm & r, CanonicalForm& multiplier, const Variable& x, 385 int coeffLevel) 386 { 387 ASSERT( x.level() > 0, "type error: polynomial variable expected" ); 388 ASSERT( ! g.isZero(), "math error: division by zero" ); 389 390 // swap variables such that x's level is larger or equal 391 // than both f's and g's levels. 392 Variable X; 393 if (f.level() > g.level()) 394 X= f.mvar(); 395 else 396 X= g.mvar(); 397 if (X.level() < x.level()) 398 X= x; 399 CanonicalForm F= swapvar (f, x, X); 400 CanonicalForm G= swapvar (g, x, X); 401 402 // now, we have to calculate the pseudo remainder of F and G 403 // w.r.t. X 404 int fDegree= degree (F, X); 405 int gDegree= degree (G, X); 406 if (fDegree < 0  fDegree < gDegree) 407 { 408 q= 0; 409 r= f; 410 } 411 else 412 { 413 CanonicalForm LCG= LC (G, X); 414 if (LCG.level() < coeffLevel) 415 { 416 multiplier= power (LCG, fDegree  gDegree + 1); 417 divrem (multiplier*F, G, q, r); 418 q= swapvar (q, x, X); 419 r= swapvar (r, x, X); 420 } 421 else 422 { 423 q= 0; 424 r= f; 425 } 426 } 427 } 428 429 /// pseudo division of f and g wrt. x s.t. multiplier*f=q*g+r 430 void 431 psqr (const CanonicalForm & f, const CanonicalForm & g, CanonicalForm & q, 432 CanonicalForm & r, CanonicalForm& multiplier, const Variable& x) 433 { 434 ASSERT( x.level() > 0, "type error: polynomial variable expected" ); 435 ASSERT( ! g.isZero(), "math error: division by zero" ); 436 437 // swap variables such that x's level is larger or equal 438 // than both f's and g's levels. 439 Variable X; 440 if (f.level() > g.level()) 441 X= f.mvar(); 442 else 443 X= g.mvar(); 444 if (X.level() < x.level()) 445 X= x; 446 CanonicalForm F= swapvar (f, x, X); 447 CanonicalForm G= swapvar (g, x, X); 448 449 // now, we have to calculate the pseudo remainder of F and G 450 // w.r.t. X 451 int fDegree= degree (F, X); 452 int gDegree= degree (G, X); 453 if (fDegree < 0  fDegree < gDegree) 454 { 455 q= 0; 456 r= f; 457 } 458 else 459 { 460 CanonicalForm LCG= LC (G, X); 461 multiplier= power (LCG, fDegree  gDegree + 1); 462 divrem (multiplier*F, G, q, r); 463 q= swapvar (q, x, X); 464 r= swapvar (r, x, X); 465 } 377 466 } 378 467
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