Functions
find_perm.cc File Reference
#include <kernel/mod2.h>
#include <omalloc/omalloc.h>
#include <polys/monomials/p_polys.h>
#include <kernel/ideals.h>
#include <polys/monomials/ring.h>
#include <kernel/maps/find_perm.h>

Go to the source code of this file.

Functions

static int * find_perm_for_map (const ring preimage_r, const ring image_r, const ideal image)
 
matrix ma_ApplyPermForMap (const matrix to_map, const ring preimage_r, const ideal image, const ring image_r, const nMapFunc nMap)
 helper function for maMapIdeal mapping ideal/matrix/module for the case of a permutation: maps the ideal/module/matrix to_map via the map from preimage_r with image image and mapping of coefficients via nMap (or return NULL) More...
 

Function Documentation

§ find_perm_for_map()

static int* find_perm_for_map ( const ring  preimage_r,
const ring  image_r,
const ideal  image 
)
static

Definition at line 20 of file find_perm.cc.

21 {
22  int i;
23  int *perm=(int *)omAlloc0((preimage_r->N+1)*sizeof(int));
24  for (i=si_min(IDELEMS(image),preimage_r->N)-1; i>=0; i--)
25  {
26  if (image->m[i]!=NULL)
27  {
28  if((pNext(image->m[i])==NULL)
29  && (n_IsOne(pGetCoeff(image->m[i]),image_r)))
30  {
31  int v=p_IsUnivariate(image->m[i],image_r);
32  if (v<=0) /*not univariate */
33  {
34  omFreeSize(perm,(preimage_r->N+1)*sizeof(int));
35  return NULL;
36  }
37  else if (v>0) /* image is univaritate */
38  {
39  if (p_GetExp(image->m[i],v,image_r)==1)
40  {
41  perm[i+1]=v; /* and of exp 1 */
42  }
43  else
44  {
45  omFreeSize(perm,(preimage_r->N+1)*sizeof(int));
46  return NULL;
47  }
48  }
49  }
50  else /* image is not a monomial */
51  {
52  omFreeSize(perm,(preimage_r->N+1)*sizeof(int));
53  return NULL;
54  }
55  }
56  }
57  //Print("elms:%d, N:%d\n",IDELEMS(image),preimage_r->N);
58  //iiWriteMatrix((matrix)image,"_",1,image_r,0);
59  //PrintS("\npreimage:\n");rWrite(preimage_r);
60  //PrintS("image:\n");rWrite(image_r);
61  //PrintS("\nperm:");
62  //for (i=1; i<=preimage_r->N; i++)
63  //{
64  // Print(" %d",perm[i]);
65  //}
66  //PrintLn();
67  return perm;
68 }
static int si_min(const int a, const int b)
Definition: auxiliary.h:124
static FORCE_INLINE BOOLEAN n_IsOne(number n, const coeffs r)
TRUE iff &#39;n&#39; represents the one element.
Definition: coeffs.h:472
#define omFreeSize(addr, size)
Definition: omAllocDecl.h:260
static number & pGetCoeff(poly p)
return an alias to the leading coefficient of p assumes that p != NULL NOTE: not copy ...
Definition: monomials.h:51
int p_IsUnivariate(poly p, const ring r)
return i, if poly depends only on var(i)
Definition: p_polys.cc:1247
static long p_GetExp(const poly p, const unsigned long iBitmask, const int VarOffset)
get a single variable exponent : the integer VarOffset encodes:
Definition: p_polys.h:464
int i
Definition: cfEzgcd.cc:123
#define IDELEMS(i)
Definition: simpleideals.h:24
const Variable & v
< [in] a sqrfree bivariate poly
Definition: facBivar.h:37
#define NULL
Definition: omList.c:10
#define pNext(p)
Definition: monomials.h:43
int perm[100]
#define omAlloc0(size)
Definition: omAllocDecl.h:211

§ ma_ApplyPermForMap()

matrix ma_ApplyPermForMap ( const matrix  to_map,
const ring  preimage_r,
const ideal  image,
const ring  image_r,
const nMapFunc  nMap 
)

helper function for maMapIdeal mapping ideal/matrix/module for the case of a permutation: maps the ideal/module/matrix to_map via the map from preimage_r with image image and mapping of coefficients via nMap (or return NULL)

Definition at line 70 of file find_perm.cc.

72 {
73  if ((rPar(preimage_r)>0)||(rPar(image_r)>0)) return NULL; /* not applicable */
74  int *perm=find_perm_for_map(preimage_r,image_r,image);
75  if (perm==NULL) return NULL; /* could not find permutation */
76  int C=to_map->cols();
77  int R=to_map->rows();
78  matrix m=mpNew(R,C);
79  for (int i=R*C-1;i>=0;i--)
80  {
81  if (to_map->m[i]!=NULL)
82  {
83  m->m[i]=p_PermPoly(to_map->m[i],perm,preimage_r,image_r, nMap,NULL,0);
84  p_Test(m->m[i],image_r);
85  }
86  }
87  ideal ii=(ideal)m;
88  ii->rank=((ideal)to_map)->rank;
89  omFreeSize(perm,(preimage_r->N+1)*sizeof(int));
90  return m;
91 }
int & rows()
Definition: matpol.h:24
static int rPar(const ring r)
(r->cf->P)
Definition: ring.h:587
#define omFreeSize(addr, size)
Definition: omAllocDecl.h:260
poly * m
Definition: matpol.h:19
poly p_PermPoly(poly p, const int *perm, const ring oldRing, const ring dst, nMapFunc nMap, const int *par_perm, int OldPar, BOOLEAN use_mult)
Definition: p_polys.cc:3939
const ring R
Definition: DebugPrint.cc:36
int m
Definition: cfEzgcd.cc:119
int i
Definition: cfEzgcd.cc:123
#define p_Test(p, r)
Definition: p_polys.h:160
matrix mpNew(int r, int c)
create a r x c zero-matrix
Definition: matpol.cc:48
int & cols()
Definition: matpol.h:25
#define NULL
Definition: omList.c:10
static int * find_perm_for_map(const ring preimage_r, const ring image_r, const ideal image)
Definition: find_perm.cc:20
int perm[100]
long rank
Definition: matpol.h:20