newtonPolygon Class Reference

#include <npolygon.h>

Public Member Functions
	newtonPolygon ()
	newtonPolygon (const newtonPolygon &)
	newtonPolygon (poly, const ring r)
	~newtonPolygon ()
newtonPolygon &	operator= (const newtonPolygon &)
void	copy_new (int)
void	copy_delete (void)
void	copy_zero (void)
void	copy_shallow (newtonPolygon &)
void	copy_deep (const newtonPolygon &)
void	add_linearForm (const linearForm &)
Rational	weight (poly, const ring r) const
Rational	weight_shift (poly, const ring r) const
Rational	weight1 (poly, const ring r) const
Rational	weight_shift1 (poly, const ring r) const

Private Attributes
linearForm *	l
int	N

Detailed Description

Definition at line 61 of file npolygon.h.

Constructor & Destructor Documentation

newtonPolygon() [1/3]

newtonPolygon::newtonPolygon ( )

inline

Definition at line 165 of file npolygon.h.

{
    copy_zero( );
}

newtonPolygon() [2/3]

newtonPolygon::newtonPolygon

(

const newtonPolygon &

np

)

Definition at line 367 of file npolygon.cc.

{
  copy_deep( np );
}

newtonPolygon() [3/3]

newtonPolygon::newtonPolygon	(	poly	f,
		const ring	r )

Definition at line 397 of file npolygon.cc.

{
  copy_zero( );
 
  int *r=new int[s->N];
  poly *m=new poly[s->N];
 
 
  KMatrix<Rational> mat(s->N,s->N+1 );
 
  int i,j,stop=FALSE;
  linearForm sol;
 
  // ---------------
  //  init counters
  // ---------------
 
  for( i=0; i<s->N; i++ )
  {
    r[i] = i;
  }
 
  m[0] = f;
 
  for( i=1; i<s->N; i++ )
  {
    m[i] = pNext(m[i-1]);
  }
 
  // -----------------------------
  //  find faces (= linear forms)
  // -----------------------------
 
  do
  {
    // ---------------------------------------------------
    //  test if monomials p.m[r[0]]m,...,p.m[r[p.vars-1]]
    //  are linearely independent
    // ---------------------------------------------------
 
    for( i=0; i<s->N; i++ )
    {
      for( j=0; j<s->N; j++ )
      {
        //    mat.set( i,j,pGetExp( m[r[i]],j+1 ) );
        mat.set( i,j,p_GetExp( m[i],j+1,s ) );
      }
      mat.set( i,j,1 );
    }
 
    if( mat.solve( &(sol.c),&(sol.N) ) == s->N )
    {
      // ---------------------------------
      //  check if linearForm is positive
      //  check if linearForm is extremal
      // ---------------------------------
 
      if( sol.positive( ) && sol.pweight( f,s ) >= (Rational)1 )
      {
        // ----------------------------------
        //  this is a face or the polyhedron
        // ----------------------------------
 
        add_linearForm( sol );
        sol.c = (Rational*)NULL;
        sol.N = 0;
      }
    }
 
    // --------------------
    //  increment counters
    // --------------------
 
    for( i=1; r[i-1] + 1 == r[i] && i < s->N; i++ );
 
    for( j=0; j<i-1; j++ )
    {
      r[j]=j;
    }
 
    if( i>1 )
    {
      m[0]=f;
      for( j=1; j<i-1; j++ )
      {
        m[j]=pNext(m[j-1]);
      }
    }
    r[i-1]++;
    m[i-1]=pNext(m[i-1]);
 
    if( m[s->N-1] == (poly)NULL )
    {
      stop = TRUE;
    }
  } while( stop == FALSE );
}

~newtonPolygon()

newtonPolygon::~newtonPolygon

(

)

Definition at line 376 of file npolygon.cc.

{
  copy_delete( );
}

Member Function Documentation

add_linearForm()

void newtonPolygon::add_linearForm

(

const linearForm &

l0

)

Definition at line 525 of file npolygon.cc.

{
  int           i;
  newtonPolygon np;
 
  // -------------------------------------
  //  test if linear form is already here
  // -------------------------------------
 
  for( i=0; i<N; i++ )
  {
    if( l0==l[i] )
    {
      return;
    }
  }
 
  np.copy_new( N+1 );
  np.N = N+1;
 
  for( i=0; i<N; i++ )
  {
    np.l[i].copy_shallow( l[i] );
    l[i].copy_zero( );
  }
 
  np.l[N] = l0;
 
  copy_delete( );
  copy_shallow( np );
  np.copy_zero( );
 
  return;
}

copy_deep()

void newtonPolygon::copy_deep

(

const newtonPolygon &

np

)

Definition at line 353 of file npolygon.cc.

{
  copy_new( np.N );
  for( int i=0; i<np.N; i++ )
  {
    l[i] = np.l[i];
  }
  N = np.N;
}

copy_delete()

void newtonPolygon::copy_delete

(

void

)

Definition at line 342 of file npolygon.cc.

{
  if( l != (linearForm*)NULL && N > 0 )
    delete [] l;
  copy_zero( );
}

copy_new()

void newtonPolygon::copy_new

(

int

k

)

Definition at line 296 of file npolygon.cc.

{
  if( k > 0 )
  {
    l = new linearForm[k];
 
    #ifndef SING_NDEBUG
      if( l == (linearForm*)NULL )
      {
        #ifdef  NPOLYGON_PRINT
          #ifdef  NPOLYGON_IOSTREAM
            cerr <<
            "void newtonPolygon::copy_new( int k ): no memory left ...\n";
          #else
            fprintf( stderr,
            "void newtonPolygon::copy_new( int k ): no memory left ...\n" );
          #endif
        #endif
 
        HALT();
      }
    #endif
  }
  else if( k == 0 )
  {
    l = (linearForm*)NULL;
  }
  else if( k < 0 )
  {
    #ifdef  NPOLYGON_PRINT
      #ifdef  NPOLYGON_IOSTREAM
        cerr << "void newtonPolygon::copy_new( int k ): k < 0 ...\n";
      #else
        fprintf( stderr,
        "void newtonPolygon::copy_new( int k ): k < 0 ...\n" );
      #endif
    #endif
 
    HALT();
  }
}

copy_shallow()

void newtonPolygon::copy_shallow ( newtonPolygon & np )

inline

Definition at line 154 of file npolygon.h.

{
    l = np.l;
    N = np.N;
}

copy_zero()

void newtonPolygon::copy_zero ( void )

inline

Definition at line 144 of file npolygon.h.

{
    l = (linearForm*)NULL;
    N = 0;
}

operator=()

newtonPolygon & newtonPolygon::operator=

(

const newtonPolygon &

np

)

Definition at line 385 of file npolygon.cc.

{
  copy_delete( );
  copy_deep( np );
 
  return *this;
}

weight()

Rational newtonPolygon::weight	(	poly	m,
		const ring	r ) const

Definition at line 564 of file npolygon.cc.

{
  Rational ret = l[0].weight( m,r );
  Rational tmp;
 
  for( int i=1; i<N; i++ )
  {
    tmp = l[i].weight( m,r );
 
    if( tmp < ret )
    {
      ret = tmp;
    }
  }
  return ret;
}

weight1()

Rational newtonPolygon::weight1	(	poly	m,
		const ring	r ) const

Definition at line 606 of file npolygon.cc.

{
  Rational ret = l[0].weight1( m, r );
  Rational tmp;
 
  for( int i=1; i<N; i++ )
  {
    tmp = l[i].weight1( m, r );
 
    if( tmp < ret )
    {
      ret = tmp;
    }
  }
  return ret;
}

weight_shift()

Rational newtonPolygon::weight_shift	(	poly	m,
		const ring	r ) const

Definition at line 585 of file npolygon.cc.

{
  Rational ret = l[0].weight_shift( m, r );
  Rational tmp;
 
  for( int i=1; i<N; i++ )
  {
    tmp = l[i].weight_shift( m, r );
 
    if( tmp < ret )
    {
      ret = tmp;
    }
  }
  return ret;
}

weight_shift1()

Rational newtonPolygon::weight_shift1	(	poly	m,
		const ring	r ) const

Definition at line 628 of file npolygon.cc.

{
  Rational ret = l[0].weight_shift1( m, r );
  Rational tmp;
 
  for( int i=1; i<N; i++ )
  {
    tmp = l[i].weight_shift1( m, r );
 
    if( tmp < ret )
    {
      ret = tmp;
    }
  }
  return ret;
}

Field Documentation

l

linearForm* newtonPolygon::l

private

Definition at line 66 of file npolygon.h.

N

int newtonPolygon::N

private

Definition at line 67 of file npolygon.h.

---

The documentation for this class was generated from the following files:

• kernel/spectrum/npolygon.h
• kernel/spectrum/npolygon.cc