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Functions
groebnerFan.h File Reference
#include "gfanlib/gfanlib_zfan.h"

Go to the source code of this file.

Functions

gfan::ZFan * groebnerFanOfPolynomial (poly g, ring r, bool onlyLowerHalfSpace=false)
 
BOOLEAN groebnerFan (leftv res, leftv args)
 

Function Documentation

◆ groebnerFan()

BOOLEAN groebnerFan ( leftv  res,
leftv  args 
)

Definition at line 85 of file groebnerFan.cc.

86 {
87  leftv u = args;
88  if ((u!=NULL) && (u->Typ()==IDEAL_CMD))
89  {
90  ideal I = (ideal) u->CopyD();
91  leftv v = u->next;
92 
93  if (v==NULL)
94  {
95  if ((I->m[0]!=NULL) && (idElem(I)==1))
96  {
97  try
98  {
99  poly g = I->m[0];
100  gfan::ZFan* zf = groebnerFanOfPolynomial(g,currRing);
101  res->rtyp = fanID;
102  res->data = (char*) zf;
103  return FALSE;
104  }
105  catch (const std::exception& ex)
106  {
107  WerrorS("ERROR: "); WerrorS(ex.what()); WerrorS("\n");
108  return TRUE;
109  }
110  }
111  else
112  {
113  try
114  {
115  tropicalStrategy currentStrategy(I,currRing);
116  setOptionRedSB();
117  gfan::ZFan* zf = groebnerFan(currentStrategy);
119  res->rtyp = fanID;
120  res->data = (char*) zf;
121  return FALSE;
122  }
123  catch (const std::exception& ex)
124  {
125  WerrorS("ERROR: "); WerrorS(ex.what()); WerrorS("\n");
126  return TRUE;
127  }
128  }
129  }
130  }
131  if ((u!=NULL) && (u->Typ()==POLY_CMD))
132  {
133  poly g = (poly) u->Data();
134  leftv v = u->next;
135  if (v==NULL)
136  {
137  try
138  {
139  gfan::ZFan* zf = groebnerFanOfPolynomial(g,currRing);
140  res->rtyp = fanID;
141  res->data = (char*) zf;
142  return FALSE;
143  }
144  catch (const std::exception& ex)
145  {
146  WerrorS("ERROR: "); WerrorS(ex.what()); WerrorS("\n");
147  return TRUE;
148  }
149  }
150  }
151  WerrorS("groebnerFan: unexpected parameters");
152  return TRUE;
153 }

◆ groebnerFanOfPolynomial()

gfan::ZFan* groebnerFanOfPolynomial ( poly  g,
ring  r,
bool  onlyLowerHalfSpace = false 
)

Definition at line 36 of file groebnerFan.cc.

37 {
38  int n = rVar(r);
39 
40  if (g==NULL || g->next==NULL)
41  {
42  // if g is a term or zero, return the fan consisting of the whole weight space
43  gfan::ZFan* zf = new gfan::ZFan(gfan::ZFan::fullFan(n));
44  return zf;
45  }
46  else
47  {
48  gfan::ZVector lowerHalfSpaceCondition = gfan::ZVector(n);
49  lowerHalfSpaceCondition[0] = -1;
50 
51  // otherwise, obtain a list of all the exponent vectors
52  int* expv = (int*) omAlloc((n+1)*sizeof(int));
53  gfan::ZMatrix exponents = gfan::ZMatrix(0,n);
54  for (poly s=g; s; pIter(s))
55  {
56  p_GetExpV(s,expv,r);
57  gfan::ZVector zv = intStar2ZVector(n,expv);
58  exponents.appendRow(intStar2ZVector(n,expv));
59  }
60  omFreeSize(expv,(n+1)*sizeof(int));
61 
62  // and construct the Groebner fan
63  gfan::ZFan* zf = new gfan::ZFan(n);
64  int l = exponents.getHeight();
65  for (int i=0; i<l; i++)
66  {
67  // constructs the Groebner cone such that initial form is i-th term
68  gfan::ZMatrix inequalities = gfan::ZMatrix(0,n);
69  if (onlyLowerHalfSpace)
70  inequalities.appendRow(lowerHalfSpaceCondition);
71  for (int j=0; j<l; j++)
72  {
73  if (i!=j)
74  inequalities.appendRow(exponents[i].toVector()-exponents[j].toVector());
75  }
76  gfan::ZCone zc = gfan::ZCone(inequalities,gfan::ZMatrix(0,inequalities.getWidth()));
77  zc.canonicalize();
78  zf->insert(zc);
79  }
80  return zf;
81  }
82 }
FALSE
#define FALSE
Definition: auxiliary.h:94
idElem
int idElem(const ideal F)
count non-zero elements
Definition: simpleideals.cc:210
sleftv::Data
void * Data()
Definition: subexpr.cc:1182
j
int j
Definition: facHensel.cc:105
setOptionRedSB
static void setOptionRedSB()
Definition: groebnerFan.cc:14
g
g
Definition: cfModGcd.cc:4031
sleftv
Class used for (list of) interpreter objects.
Definition: subexpr.h:83
undoSetOptionRedSB
static void undoSetOptionRedSB()
Definition: groebnerFan.cc:23
intStar2ZVector
gfan::ZVector intStar2ZVector(const int d, const int *i)
Definition: callgfanlib_conversion.cc:86
fullFan
BOOLEAN fullFan(leftv res, leftv args)
Definition: bbfan.cc:228
currRing
ring currRing
Widely used global variable which specifies the current polynomial ring for Singular interpreter and ...
Definition: polys.cc:13
rVar
static short rVar(const ring r)
#define rVar(r) (r->N)
Definition: ring.h:582
TRUE
#define TRUE
Definition: auxiliary.h:98
i
int i
Definition: cfEzgcd.cc:125
res
CanonicalForm res
Definition: facAbsFact.cc:64
groebnerFanOfPolynomial
gfan::ZFan * groebnerFanOfPolynomial(poly g, ring r, bool onlyLowerHalfSpace=false)
Definition: groebnerFan.cc:36
omFreeSize
#define omFreeSize(addr, size)
Definition: omAllocDecl.h:260
IDEAL_CMD
@ IDEAL_CMD
Definition: grammar.cc:284
pIter
#define pIter(p)
Definition: monomials.h:38
omAlloc
#define omAlloc(size)
Definition: omAllocDecl.h:210
p_GetExpV
static void p_GetExpV(poly p, int *ev, const ring r)
Definition: p_polys.h:1457
inequalities
BOOLEAN inequalities(leftv res, leftv args)
Definition: bbcone.cc:560
groebnerFan
gfan::ZFan * groebnerFan(const tropicalStrategy currentStrategy)
Definition: groebnerFan.cc:28
WerrorS
void WerrorS(const char *s)
Definition: feFopen.cc:24
sleftv::Typ
int Typ()
Definition: subexpr.cc:1039
NULL
#define NULL
Definition: omList.c:10
sleftv::CopyD
void * CopyD(int t)
Definition: subexpr.cc:745
l
int l
Definition: cfEzgcd.cc:93
v
const Variable & v
< [in] a sqrfree bivariate poly
Definition: facBivar.h:37
s
const CanonicalForm int s
Definition: facAbsFact.cc:55
POLY_CMD
@ POLY_CMD
Definition: grammar.cc:289
fanID
int fanID
Definition: bbfan.cc:19
sleftv::next
leftv next
Definition: subexpr.h:86
tropicalStrategy
Definition: tropicalStrategy.h:37