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khstd.cc
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1 /****************************************
2 * Computer Algebra System SINGULAR *
3 ****************************************/
4 /*
5 * ABSTRACT:utils for hilbert driven kStd
6 */
7 
8 #include "kernel/mod2.h"
9 
10 #include "misc/options.h"
11 #include "misc/intvec.h"
12 
13 #include "polys/simpleideals.h"
14 
17 
18 #include "kernel/GBEngine/kutil.h"
19 #include "kernel/GBEngine/kstd1.h"
20 #include "kernel/GBEngine/khstd.h"
21 
22 #include "kernel/polys.h"
23 
24 /*2
25 * compare the given hilbert series with the current one,
26 * delete not needed pairs (if possible)
27 */
28 void khCheck( ideal Q, intvec *w, intvec *hilb, int &eledeg, int &count,
29  kStrategy strat)
30  /* ideal S=strat->Shdl, poly p=strat->P.p */
31 /*
32 * compute the number eledeg of elements with a degree >= deg(p) going into kStd,
33 * p is already in S and for all further q going into S yields deg(q) >= deg(p),
34 * the real computation is only done if the degree has changed,
35 * then we have eledeg == 0 on this degree and we make:
36 * - compute the Hilbert series newhilb from S
37 * (hilb is the final Hilbert series)
38 * - in module case: check that all comp up to strat->ak are used
39 * - compute the eledeg from newhilb-hilb for the first degree deg with
40 * newhilb-hilb != 0
41 * (Remark: consider the Hilbert series with coeff. up to infinity)
42 * - clear the set L for degree < deg
43 * the number count is only for statistics (in the caller initialise count = 0),
44 * in order to get a first computation, initialise eledeg = 1 in the caller.
45 * The weights w are needed in the module case, otherwise NULL.
46 */
47 {
48  intvec *newhilb;
49  int deg,l,ln,mw;
50  pFDegProc degp;
51 
52  eledeg--;
53  if (eledeg == 0)
54  {
55  if (strat->ak>0)
56  {
57  char *used_comp=(char*)omAlloc0(strat->ak+1);
58  int i;
59  for(i=strat->sl;i>0;i--)
60  {
61  used_comp[pGetComp(strat->S[i])]='\1';
62  }
63  for(i=strat->ak;i>0;i--)
64  {
65  if(used_comp[i]=='\0')
66  {
67  omFree((ADDRESS)used_comp);
68  return;
69  }
70  }
71  omFree((ADDRESS)used_comp);
72  }
73  degp=currRing->pFDeg;
74  // if weights for variables were given to std computations,
75  // then pFDeg == degp == kHomModDeg (see kStd)
76  if ((degp!=kModDeg) && (degp!=kHomModDeg)) degp=p_Totaldegree;
77  // degp = pWDegree;
78  l = hilb->length()-1;
79  mw = (*hilb)[l];
80  newhilb = hHstdSeries(strat->Shdl,w,strat->kHomW,Q,strat->tailRing);
81  ln = newhilb->length()-1;
82  deg = degp(strat->P.p,currRing)-mw;
83  loop // compare the series in degree deg, try to increase deg -----------
84  {
85  if (deg < ln) // deg may be out of range
86  {
87  if (deg < l)
88  eledeg = (*newhilb)[deg]-(*hilb)[deg];
89  else
90  eledeg = (*newhilb)[deg];
91  }
92  else
93  {
94  if (deg < l)
95  eledeg = -(*hilb)[deg];
96  else // we have newhilb = hilb
97  {
98  while (strat->Ll>=0)
99  {
100  count++;
101  if(TEST_OPT_PROT)
102  {
103  PrintS("h");
104  mflush();
105  }
106  deleteInL(strat->L,&strat->Ll,strat->Ll,strat);
107  }
108  delete newhilb;
109  return;
110  }
111  }
112  if (eledeg > 0) // elements to delete
113  break;
114  else if (eledeg <0) // strange....see bug_43
115  return;
116  deg++;
117  } /* loop */
118  delete newhilb;
119  while ((strat->Ll>=0) && (degp(strat->L[strat->Ll].p,currRing)-mw < deg)) // the essential step
120  {
121  count++;
122  if(TEST_OPT_PROT)
123  {
124  PrintS("h");
125  mflush();
126  }
127  deleteInL(strat->L,&strat->Ll,strat->Ll,strat);
128  }
129  }
130 }
131 
132 
133 void khCheckLocInhom(ideal Q, intvec *w, intvec *hilb, int &count,
134  kStrategy strat)
135 
136 /*
137 This will be used for the local orderings in the case of the inhomogenous ideals.
138 Assume f1,...,fs are already in the standard basis. Test if hilb(LM(f1),...,LM(fs),1)
139 is equal to the inputed one.
140 If no, do nothing.
141 If Yes, we know that all polys that we need are already in the standard basis
142 so delete all the remaining pairs
143 */
144 {
145  ideal Lm;
146  intvec *newhilb;
147 
148  Lm = id_Head(strat->Shdl,currRing);
149 
150  newhilb =hHstdSeries(Lm,w,strat->kHomW,Q,currRing); // ,strat->tailRing?
151 
152  if(newhilb->compare(hilb) == 0)
153  {
154  while (strat->Ll>=0)
155  {
156  count++;
157  if(TEST_OPT_PROT)
158  {
159  PrintS("h");
160  mflush();
161  }
162  deleteInL(strat->L,&strat->Ll,strat->Ll,strat);
163  }
164  delete newhilb;
165  return;
166  }
167  id_Delete(&Lm,currRing);
168 }
void * ADDRESS
Definition: auxiliary.h:119
int l
Definition: cfEzgcd.cc:100
int i
Definition: cfEzgcd.cc:132
Definition: intvec.h:23
int length() const
Definition: intvec.h:94
int compare(const intvec *o) const
Definition: intvec.cc:206
ring tailRing
Definition: kutil.h:343
int Ll
Definition: kutil.h:351
polyset S
Definition: kutil.h:306
int ak
Definition: kutil.h:353
intvec * kHomW
Definition: kutil.h:336
ideal Shdl
Definition: kutil.h:303
LObject P
Definition: kutil.h:302
LSet L
Definition: kutil.h:327
int sl
Definition: kutil.h:348
const CanonicalForm & w
Definition: facAbsFact.cc:51
intvec * hHstdSeries(ideal S, intvec *modulweight, intvec *wdegree, ideal Q, ring tailRing)
Definition: hilb.cc:1366
STATIC_VAR jList * Q
Definition: janet.cc:30
void khCheckLocInhom(ideal Q, intvec *w, intvec *hilb, int &count, kStrategy strat)
Definition: khstd.cc:133
void khCheck(ideal Q, intvec *w, intvec *hilb, int &eledeg, int &count, kStrategy strat)
Definition: khstd.cc:28
long kModDeg(poly p, ring r)
Definition: kstd1.cc:2410
long kHomModDeg(poly p, ring r)
Definition: kstd1.cc:2420
void deleteInL(LSet set, int *length, int j, kStrategy strat)
Definition: kutil.cc:1270
#define omFree(addr)
Definition: omAllocDecl.h:261
#define omAlloc0(size)
Definition: omAllocDecl.h:211
#define TEST_OPT_PROT
Definition: options.h:103
static long p_Totaldegree(poly p, const ring r)
Definition: p_polys.h:1479
VAR ring currRing
Widely used global variable which specifies the current polynomial ring for Singular interpreter and ...
Definition: polys.cc:13
Compatiblity layer for legacy polynomial operations (over currRing)
#define pGetComp(p)
Component.
Definition: polys.h:37
void PrintS(const char *s)
Definition: reporter.cc:284
#define mflush()
Definition: reporter.h:58
long(* pFDegProc)(poly p, ring r)
Definition: ring.h:38
int status int void size_t count
Definition: si_signals.h:59
void id_Delete(ideal *h, ring r)
deletes an ideal/module/matrix
ideal id_Head(ideal h, const ring r)
returns the ideals of initial terms
#define loop
Definition: structs.h:79