Changeset 5dad8b3 in git for kernel/polys.cc
 Timestamp:
 Nov 10, 2010, 3:16:13 PM (12 years ago)
 Branches:
 (u'jengelhdatetime', 'ceac47cbc86fe4a15902392bdbb9bd2ae0ea02c6')(u'spielwiese', 'a800fe4b3e9d37a38c5a10cc0ae9dfa0c15a4ee6')
 Children:
 1446e7f6b858dd03816a2e1b9a0c6022428f8b67
 Parents:
 40157303341732339fd6bc4f53baf18c09715ae0
 File:

 1 edited
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kernel/polys.cc
r4015730 r5dad8b3 275 275 } 276 276 #endif 277 278 277 p_Setm(rc,r); 279 278 } 280 finish: 279 finish: 281 280 return s; 282 281 } … … 354 353 } 355 354 355 /*4 356 *Returns the exponent of the maximal power of the leading monomial of 357 *p2 in that of p1 358 */ 359 static int pGetMaxPower (poly p1,poly p2) 360 { 361 int i,k,res = 32000; /*a very large integer*/ 362 363 if (p1 == NULL) return 0; 364 for (i=1; i<=pVariables; i++) 365 { 366 if ( pGetExp(p2,i) != 0) 367 { 368 k = pGetExp(p1,i) / pGetExp(p2,i); 369 if (k < res) res = k; 370 } 371 } 372 return res; 373 } 374 375 /*2 376 *returns the leading monomial of p1 divided by the maximal power of that 377 *of p2 378 */ 379 static poly pDivByMonom (poly p1,poly p2) 380 { 381 int k, i; 382 383 if (p1 == NULL) return NULL; 384 k = pGetMaxPower(p1,p2); 385 if (k == 0) 386 return pHead(p1); 387 else 388 { 389 number n; 390 poly p = pInit(); 391 392 p>next = NULL; 393 for (i=1; i<=pVariables; i++) 394 { 395 pSetExp(p,i, pGetExp(p1,i)k* pGetExp(p2,i)); 396 } 397 nPower(p2>coef,k,&n); 398 pSetCoeff0(p,nDiv(p1>coef,n)); 399 nDelete(&n); 400 pSetm(p); 401 return p; 402 } 403 } 404 // Returns as ith entry of P the coefficient of the (i1) power of 405 // the leading monomial of p2 in p1 406 // 407 static void pCancelPolyByMonom (poly p1,poly p2,polyset * P,int * SizeOfSet) 408 { 409 int maxPow; 410 poly p,qp,Coeff; 411 412 if (*P == NULL) 413 { 414 *P = (polyset) omAlloc(5*sizeof(poly)); 415 *SizeOfSet = 5; 416 } 417 p = pCopy(p1); 418 while (p != NULL) 419 { 420 qp = p>next; 421 p>next = NULL; 422 maxPow = pGetMaxPower(p,p2); 423 Coeff = pDivByMonom(p,p2); 424 if (maxPow > *SizeOfSet) 425 { 426 pEnlargeSet(P,*SizeOfSet,maxPow+1*SizeOfSet); 427 *SizeOfSet = maxPow+1; 428 } 429 (*P)[maxPow] = pAdd((*P)[maxPow],Coeff); 430 pDelete(&p); 431 p = qp; 432 } 433 } 356 434 /*2 357 435 *replaces the maximal powers of the leading monomial of p2 in p1 by … … 389 467 } 390 468 391 /*4 392 *Returns the exponent of the maximal power of the leading monomial of 393 *p2 in that of p1 394 */ 395 static int pGetMaxPower (poly p1,poly p2) 396 { 397 int i,k,res = 32000; /*a very large integer*/ 398 399 if (p1 == NULL) return 0; 400 for (i=1; i<=pVariables; i++) 401 { 402 if ( pGetExp(p2,i) != 0) 403 { 404 k = pGetExp(p1,i) / pGetExp(p2,i); 405 if (k < res) res = k; 406 } 407 } 408 return res; 409 } 410 411 /*2 412 *Returns as ith entry of P the coefficient of the (i1) power of 413 *the leading monomial of p2 in p1 414 */ 415 void pCancelPolyByMonom (poly p1,poly p2,polyset * P,int * SizeOfSet) 416 { 417 int maxPow; 418 poly p,qp,Coeff; 419 420 if (*P == NULL) 421 { 422 *P = (polyset) omAlloc(5*sizeof(poly)); 423 *SizeOfSet = 5; 424 } 425 p = pCopy(p1); 426 while (p != NULL) 427 { 428 qp = p>next; 429 p>next = NULL; 430 maxPow = pGetMaxPower(p,p2); 431 Coeff = pDivByMonom(p,p2); 432 if (maxPow > *SizeOfSet) 433 { 434 pEnlargeSet(P,*SizeOfSet,maxPow+1*SizeOfSet); 435 *SizeOfSet = maxPow+1; 436 } 437 (*P)[maxPow] = pAdd((*P)[maxPow],Coeff); 438 pDelete(&p); 439 p = qp; 440 } 441 } 442 443 /*2 444 *returns the leading monomial of p1 divided by the maximal power of that 445 *of p2 446 */ 447 poly pDivByMonom (poly p1,poly p2) 448 { 449 int k, i; 450 451 if (p1 == NULL) return NULL; 452 k = pGetMaxPower(p1,p2); 453 if (k == 0) 454 return pHead(p1); 455 else 456 { 457 number n; 458 poly p = pInit(); 459 460 p>next = NULL; 461 for (i=1; i<=pVariables; i++) 462 { 463 pSetExp(p,i, pGetExp(p1,i)k* pGetExp(p2,i)); 464 } 465 nPower(p2>coef,k,&n); 466 pSetCoeff0(p,nDiv(p1>coef,n)); 467 nDelete(&n); 468 pSetm(p); 469 return p; 470 } 471 } 469 472 470 /*utilities for syzygies*/ 473 471 poly pTakeOutComp(poly * p, int k)
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