source: git/kernel/shiftgb.cc @ 037df4

fieker-DuValspielwiese
Last change on this file since 037df4 was 037df4, checked in by Hans Schönemann <hannes@…>, 16 years ago
*hannes: HAVE_SHIFTBBA git-svn-id: file:///usr/local/Singular/svn/trunk@10850 2c84dea3-7e68-4137-9b89-c4e89433aadc
  • Property mode set to 100644
File size: 12.9 KB
Line 
1/****************************************
2*  Computer Algebra System SINGULAR     *
3****************************************/
4/* $Id: shiftgb.cc,v 1.8 2008-07-08 13:02:21 Singular Exp $ */
5/*
6* ABSTRACT: kernel: utils for shift GB and free GB
7*/
8
9#include "mod2.h"
10
11#ifdef HAVE_SHIFTBBA
12#include "febase.h"
13#include "ring.h"
14#include "polys.h"
15#include "numbers.h"
16#include "ideals.h"
17#include "matpol.h"
18#include "kbuckets.h"
19#include "kstd1.h"
20#include "sbuckets.h"
21#include "p_Mult_q.h"
22#include "kutil.h"
23#include "structs.h"
24#include "omalloc.h"
25#include "khstd.h"
26#include "kbuckets.h"
27#include "weight.h"
28#include "intvec.h"
29#include "structs.h"
30#include "kInline.cc"
31#include "stairc.h"
32#include "weight.h"
33#include "intvec.h"
34#include "timer.h"
35#include "shiftgb.h"
36#include "sca.h"
37
38
39#define freeT(A,v) omFreeSize((ADDRESS)A,(v+1)*sizeof(int))
40
41
42/* TODO: write p* stuff as instances of p_* for all the functions */
43/* p_* functions are new, p* are old */
44
45poly p_LPshiftT(poly p, int sh, int uptodeg, int lV, kStrategy strat, const ring r)
46{
47  /* assume shift takes place, shifts the poly p by sh */
48  /* p is like TObject: lm in currRing = r, tail in tailRing  */
49
50  if (p==NULL) return(p);
51
52  assume(p_LmCheckIsFromRing(p,r));
53  assume(p_CheckIsFromRing(pNext(p),strat->tailRing));
54
55  /* assume sh and uptodeg agree  TODO check */
56
57  if (sh == 0) return(p); /* the zero shift */
58
59  poly q   = NULL;
60  poly s   = p_mLPshift(p, sh, uptodeg, lV, r); // lm in currRing
61  poly pp = pNext(p);
62 
63  while (pp != NULL)
64  {
65    q = p_Add_q(q, p_mLPshift(pp,sh,uptodeg,lV,strat->tailRing),strat->tailRing);
66    pIter(pp);
67  }
68  pNext(s) = q;
69  /* int version: returns TRUE if it was successful */
70  return(s);
71}
72
73
74poly p_LPshift(poly p, int sh, int uptodeg, int lV, const ring r)
75{
76  /* assume shift takes place */
77  /* shifts the poly p from the ring r by sh */
78
79  /* assume sh and uptodeg agree TODO check */
80
81  if (p==NULL) return(p);
82  if (sh == 0) return(p); /* the zero shift */
83
84  poly q  = NULL;
85  poly pp = p; // do not take copies
86  while (pp!=NULL)
87  {
88    q = p_Add_q(q, p_mLPshift(pp,sh,uptodeg,lV,r),r);
89    pIter(pp);
90  }
91  return(q);
92}
93
94poly p_mLPshift(poly p, int sh, int uptodeg, int lV, const ring r)
95{
96  /* p is a monomial from the ring r */
97
98  if (sh == 0) return(p); /* the zero shift */
99
100  if (sh < 0 )
101  {
102#ifdef PDEBUG
103    Print("pmLPshift: negative shift requested");
104#endif
105    return(NULL); /* violation, 2check */
106  }
107
108  int L = p_mLastVblock(p,lV,r);
109  if (L+sh-1 > uptodeg)
110  {
111#ifdef PDEBUG
112    Print("p_mLPshift: too big shift requested");
113#endif
114    return(NULL); /* violation, 2check */
115  }
116  int *e=(int *)omAlloc0((r->N+1)*sizeof(int));
117  int *s=(int *)omAlloc0((r->N+1)*sizeof(int));
118  p_GetExpV(p,e,r);
119
120  int j;
121  //  for (j=1; j<=r->N; j++)
122  // L*lV gives the last position of the last block
123  for (j=1; j<= L*lV ; j++)
124  {
125    if (e[j]==1)
126    {
127      s[j + (sh*lV)] = e[j]; /* actually 1 */
128#ifdef PDEBUG
129      omCheckAddr(s);
130#endif
131    }
132#ifdef PDEBUG
133    else 
134    {
135      if (e[j]!=0)
136      {
137        //         Print("p_mLPshift: ex[%d]=%d\n",j,e[j]);
138      }
139    }
140#endif
141  }
142  poly m = p_ISet(1,r);
143  p_SetExpV(m,s,r);
144  freeT(e, r->N);
145  freeT(s, r->N);
146  /*  pSetm(m); */ /* done in the pSetExpV */
147  /* think on the component and coefficient */
148  //  number c = pGetCoeff(p);
149  //  p_SetCoeff0(m,p_GetCoeff(p,r),r);
150  p_SetComp(m,p_GetComp(p,r),r); // component is preserved
151  p_SetCoeff0(m,p_GetCoeff(p,r),r);  // coeff is preserved
152  return(m);
153}
154
155poly pLPshift(poly p, int sh, int uptodeg, int lV)
156{
157  /* assume shift takes place */
158  /* shifts the poly p by sh */
159  /* deletes p */
160
161  /* assume sh and uptodeg agree */
162
163  if (sh == 0) return(p); /* the zero shift */
164
165  poly q  = NULL;
166  poly pp = p; // pCopy(p);
167  while (pp!=NULL)
168  {
169    q = p_Add_q(q, pmLPshift(pp,sh,uptodeg,lV),currRing);
170    pIter(pp);
171  }
172  /* delete pp? */
173  /* int version: returns TRUE if it was successful */
174  return(q);
175}
176
177poly pmLPshift(poly p, int sh, int uptodeg, int lV)
178{
179  /* TODO: use a shortcut with p_ version */
180  /* pm is a monomial */
181
182  if (sh == 0) return(p); /* the zero shift */
183
184  if (sh < 0 )
185  {
186#ifdef PDEBUG
187    Print("pmLPshift: negative shift requested");
188#endif
189    return(NULL); /* violation, 2check */
190  }
191
192  int L = pmLastVblock(p,lV);
193  if (L+sh-1 > uptodeg)
194  {
195#ifdef PDEBUG
196    Print("pmLPshift: too big shift requested");
197#endif
198    return(NULL); /* violation, 2check */
199  }
200  int *e=(int *)omAlloc0((currRing->N+1)*sizeof(int));
201  int *s=(int *)omAlloc0((currRing->N+1)*sizeof(int));
202  pGetExpV(p,e);
203  number c = pGetCoeff(p);
204  int j;
205  for (j=1; j<=currRing->N; j++)
206  {
207    if (e[j]==1)
208    {
209      s[j + (sh*lV)] = e[j]; /* actually 1 */
210    }
211  }
212  poly m = pOne();
213  pSetExpV(m,s);
214  /*  pSetm(m); */ /* done in the pSetExpV */
215  /* think on the component */
216  pSetCoeff0(m,c);
217  freeT(e, currRing->N);
218  freeT(s, currRing->N);
219  return(m);
220}
221
222int pLastVblock(poly p, int lV)
223{
224  /* returns the number of maximal block */
225  /* appearing among the monomials of p */
226  /* the 0th block is the 1st one */
227  poly q = p; //p_Copy(p,currRing); /* need it ? */
228  int ans = 0; 
229  int ansnew = 0;
230  while (q!=NULL)
231  {
232    ansnew = pmLastVblock(q,lV);
233    ans    = si_max(ans,ansnew);
234    pIter(q);
235  }
236  /* do not need to delete q */
237  return(ans);
238}
239
240int pmLastVblock(poly p, int lV)
241{
242  /* for a monomial p, returns the number of the last block */
243  /* where a nonzero exponent is sitting */
244  if (pIsConstantPoly(p))
245  {
246    return(int(0));
247  }
248  int *e=(int *)omAlloc0((currRing->N+1)*sizeof(int));
249  pGetExpV(p,e);
250  int j,b;
251  j = currRing->N;
252  while ( (!e[j]) && (j>=1) ) j--;
253  if (j==0) 
254  {
255#ifdef PDEBUG
256    Print("pmLastVblock: unexpected zero exponent vector");
257    PrintLn();
258#endif   
259    return(j);
260  }
261  b = (int)(j/lV) + 1; /* the number of the block, >=1 */
262  return (b);
263}
264
265int p_LastVblockT(poly p, int lV, kStrategy strat, const ring r)
266{
267  /* returns the number of maximal block */
268  /* appearing among the monomials of p */
269  /* the 0th block is the 1st one */
270
271  /* p is like TObject: lm in currRing = r, tail in tailRing  */
272  assume(p_LmCheckIsFromRing(p,r));
273  assume(p_CheckIsFromRing(pNext(p),strat->tailRing));
274
275  int ans = p_mLastVblock(p, lV, r); // Block of LM
276  poly q = pNext(p); 
277  int ansnew = 0;
278  while (q != NULL)
279  {
280    ansnew = p_mLastVblock(q, lV, strat->tailRing);
281    ans       = si_max(ans,ansnew);
282    pIter(q);
283  }
284  /* do not need to delete q */
285  return(ans);
286}
287
288int p_LastVblock(poly p, int lV, const ring r)
289{
290  /* returns the number of maximal block */
291  /* appearing among the monomials of p */
292  /* the 0th block is the 1st one */
293  poly q = p; //p_Copy(p,currRing); /* need it ? */
294  int ans = 0; 
295  int ansnew = 0;
296  while (q!=NULL)
297  {
298    ansnew = p_mLastVblock(q, lV, r);
299    ans    = si_max(ans,ansnew);
300    pIter(q);
301  }
302  /* do not need to delete q */
303  return(ans);
304}
305
306int p_mLastVblock(poly p, int lV, const ring r)
307{
308  /* for a monomial p, returns the number of the last block */
309  /* where a nonzero exponent is sitting */
310  if (p_LmIsConstant(p,r))
311  {
312    return(0);
313  }
314  int *e=(int *)omAlloc0((r->N+1)*sizeof(int));
315  p_GetExpV(p,e,r);
316  int j,b;
317  j = r->N;
318  while ( (!e[j]) && (j>=1) ) j--;
319  if (j==0) 
320  {
321#ifdef PDEBUG
322    Print("pmLastVblock: unexpected zero exponent vector");
323    PrintLn();
324#endif   
325    return(j);
326  }
327  b = (int)((j+lV-1)/lV); /* the number of the block, >=1 */
328  freeT(e,r->N);
329  return (b);
330}
331
332int pFirstVblock(poly p, int lV)
333{
334  /* returns the number of maximal block */
335  /* appearing among the monomials of p */
336  /* the 0th block is the 1st one */
337  poly q = p; //p_Copy(p,currRing); /* need it ? */
338  int ans = 0; 
339  int ansnew = 0;
340  while (q!=NULL)
341  {
342    ansnew = pmFirstVblock(q,lV);
343    ans    = si_min(ans,ansnew);
344    pIter(q);
345  }
346  /* do not need to delete q */
347  return(ans);
348}
349
350int pmFirstVblock(poly p, int lV)
351{
352  if (pIsConstantPoly(p))
353  {
354    return(int(0));
355  }
356  /* for a monomial p, returns the number of the first block */
357  /* where a nonzero exponent is sitting */
358  int *e=(int *)omAlloc0((currRing->N+1)*sizeof(int));
359  pGetExpV(p,e);
360  int j,b;
361  j = 1;
362  while ( (!e[j]) && (j<=currRing->N-1) ) j++;
363  if (j==currRing->N + 1) 
364  {
365#ifdef PDEBUG
366    Print("pmFirstVblock: unexpected zero exponent vector");
367    PrintLn();
368#endif   
369    return(j);
370  }
371  b = (int)(j/lV)+1; /* the number of the block, 1<= N <= currRing->N  */
372  return (b);
373}
374
375  /* there should be two routines: */
376  /* 1. test place-squarefreeness: in homog this suffices: isInV */
377  /* 2. test the presence of a hole -> in the tail??? */
378
379int isInV(poly p, int lV)
380{
381  /* investigate only the leading monomial of p in currRing */
382  if (lV <= 0) return(0);
383  /* returns 1 iff p is in V */
384  /* that is in each block up to a certain one there is only one nonzero exponent */
385  /* lV = the length of V = the number of orig vars */
386  int *e = (int *)omAlloc0((currRing->N+1)*sizeof(int));
387  int  b = (int)((currRing->N +lV-1)/lV); /* the number of blocks */
388  //int b  = (int)(currRing->N)/lV;
389  int *B = (int *)omAlloc0((b+1)*sizeof(int)); /* the num of elements in a block */
390  pGetExpV(p,e);
391  int i,j;
392  for (j=1; j<=b; j++)
393  {
394    /* we go through all the vars */
395    /* by blocks in lV vars */
396    for (i=(j-1)*lV + 1; i<= j*lV; i++)
397    {
398      if (e[i]) B[j] = B[j]+1;
399    }
400  }
401  //  j = b;
402  //  while ( (!B[j]) && (j>=1)) j--;
403  for (j=b; j>=1; j--)
404  {
405    if (B[j]!=0) break;
406  }
407  /* do not need e anymore */
408  freeT(e, currRing->N);
409
410  if (j==0) goto ret_true;
411//   {
412//     /* it is a zero exp vector, which is in V */
413//     freeT(B, b);
414//     return(1);
415//   }
416  /* now B[j] != 0 and we test place-squarefreeness */
417  for (j; j>=1; j--)
418  {
419    if (B[j]!=1)
420    {
421      freeT(B, b);
422      return(0);
423    }
424  }
425 ret_true:
426  freeT(B, b);
427  return(1);
428}
429
430int itoInsert(poly p, int uptodeg, int lV, const ring r)
431{
432  /* for poly in lmCR/tailTR presentation */
433  /* the below situation (commented out) might happen! */
434//   if (r == currRing)
435//   {
436//     "Current ring is not expected in toInsert";
437//     return(0);
438//   }
439  /* compute the number of insertions */
440  int i = p_mLastVblock(p, lV, currRing);
441  if (pNext(p) != NULL)
442  {
443    i = si_max(i, p_LastVblock(pNext(p), lV, r) );
444  }
445  //  i = uptodeg  - i +1;
446  i = uptodeg  - i; 
447  //  p_wrp(p,currRing,r); Print("----i:%d",i); PrintLn();
448  return(i);
449}
450
451poly p_ShrinkT(poly p, int lV, kStrategy strat, const ring r)
452//poly p_Shrink(poly p, int uptodeg, int lV, kStrategy strat, const ring r)
453{
454  /* p is like TObject: lm in currRing = r, tail in tailRing  */
455  /* proc shrinks the poly p in ring r */
456  /* lV = the length of V = the number of orig vars */
457  /* check assumes/exceptions */
458  /* r->N is a multiple of lV */
459
460  if (p==NULL) return(p);
461
462  assume(p_LmCheckIsFromRing(p,r));
463  assume(p_CheckIsFromRing(pNext(p),strat->tailRing));
464
465  poly q   = NULL;
466  poly s   = p_mShrink(p, lV, r); // lm in currRing
467  poly pp = pNext(p);
468 
469  while (pp != NULL)
470  {
471    //    q = p_Add_q(q, p_mShrink(pp,uptodeg,lV,strat->tailRing),strat->tailRing);
472    q = p_Add_q(q, p_mShrink(pp,lV,strat->tailRing),strat->tailRing);
473    pIter(pp);
474  }
475  pNext(s) = q;
476  return(s);
477}
478
479poly p_Shrink(poly p, int lV, const ring r)
480{
481  /* proc shrinks the poly p in ring r */
482  /* lV = the length of V = the number of orig vars */
483  /* check assumes/exceptions */
484  /* r->N is a multiple of lV */
485
486  if (p==NULL) return(p);
487  assume(p_CheckIsFromRing(p,r));
488  poly q = NULL;
489  poly pp = p;
490 
491  while (pp != NULL)
492  {
493    q = p_Add_q(q, p_mShrink(pp,lV,r),r);
494    pIter(pp);
495  }
496  return(q);
497}
498
499poly p_mShrink(poly p, int lV, const ring r)
500{
501  /* shrinks the monomial p in ring r */
502  /* lV = the length of V = the number of orig vars */
503
504  /* check assumes/exceptions */
505  /* r->N is a multiple of lV */
506
507  int *e = (int *)omAlloc0((r->N+1)*sizeof(int));
508  int  b = (int)((r->N +lV-1)/lV); /* the number of blocks */
509  //  int *B = (int *)omAlloc0((b+1)*sizeof(int)); /* the num of elements in a block */
510  int *S = (int *)omAlloc0((r->N+1)*sizeof(int)); /* the shrinked exponent */
511  p_GetExpV(p,e,r);
512  int i,j; int cnt = 1; //counter for blocks in S
513  for (j=1; j<=b; j++)
514  {
515    /* we go through all the vars */
516    /* by blocks in lV vars */
517    for (i=(j-1)*lV + 1; i<= j*lV; i++)
518    {
519      if (e[i]==1) 
520      {
521        //      B[j] = B[j]+1; // for control in V?
522         S[(cnt-1)*lV + (i - (j-1)*lV)] = e[i];
523         /* assuming we are in V, can interrupt here */
524         cnt++;
525         //  break; //results in incomplete shrink!
526         i = j*lV; // manual break under assumption p is in V
527      }
528    }
529  }
530#ifdef PDEBUG
531  //  Print("p_mShrink: cnt = [%d], b = %d\n",cnt,b);
532#endif
533  // cnt -1 <= b  must hold!
534  //  freeT(B, b);
535  poly s = p_ISet(1,r);
536  p_SetExpV(s,S,r);
537  freeT(e, r->N);
538  freeT(S, r->N);
539  /*  p_Setm(s,r); // done by p_SetExpV */
540  p_SetComp(s,p_GetComp(p,r),r); // component is preserved
541  p_SetCoeff(s,p_GetCoeff(p,r),r);  // coeff is preserved
542#ifdef PDEBUG
543  //  Print("p_mShrink: from "); p_wrp(p,r); Print(" to "); p_wrp(s,r); PrintLn();
544#endif
545  return(s);
546}
547
548/* shiftgb stuff */
549
550
551/* remarks: cleanT : just deletion
552enlargeT: just reallocation */
553
554#endif
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