tropicalVarietyOfPolynomials.cc File Reference

#include "gfanlib/gfanlib.h"
#include "polys/monomials/p_polys.h"
#include "callgfanlib_conversion.h"
#include "tropicalStrategy.h"
#include "tropicalVarietyOfPolynomials.h"

Go to the source code of this file.

Functions
std::set< gfan::ZCone >	tropicalVariety (const poly g, const ring r, const tropicalStrategy *currentCase)
ZConesSortedByDimension	tropicalVarietySortedByDimension (const poly g, const ring r, const tropicalStrategy *currentCase)

Function Documentation

tropicalVariety()

std::set< gfan::ZCone > tropicalVariety	(	const poly	g,
		const ring	r,
		const tropicalStrategy *	currentCase
	)

Definition at line 20 of file tropicalVarietyOfPolynomials.cc.

{
  int n = rVar(r);
  std::set<gfan::ZCone> tropVar;
  if (g && g->next)
  {
    int* expv = (int*) omAlloc((n+1)*sizeof(int));
    gfan::ZMatrix exponents = gfan::ZMatrix(0,n);
    for (poly s=g; s; pIter(s))
    {
      p_GetExpV(s,expv,r);
      gfan::ZVector zv = intStar2ZVector(n,expv);
      exponents.appendRow(intStar2ZVector(n,expv));
    }
    omFreeSize(expv,(n+1)*sizeof(int));
 
    int l = exponents.getHeight();
    gfan::ZVector lowerHalfSpaceCondition = gfan::ZVector(n);
    lowerHalfSpaceCondition[0] = -1;
    for (int i=0; i<l; i++)
    {
      for (int j=i+1; j<l; j++)
      {
        gfan::ZMatrix equation = gfan::ZMatrix(0,n);
        equation.appendRow(exponents[i].toVector()-exponents[j].toVector());
        gfan::ZMatrix inequalities = gfan::ZMatrix(0,n);
        if (currentCase->restrictToLowerHalfSpace())
          inequalities.appendRow(lowerHalfSpaceCondition);
        for (int k=0; k<l; k++)
          if (k!=i && k!=j) inequalities.appendRow(((gfan::ZVector)exponents[i])-exponents[k]);
        gfan::ZCone zc = gfan::ZCone(inequalities,equation);
        if (zc.dimension()>=n-1)
        {
          zc.canonicalize();
          tropVar.insert(zc);
        }
      }
    }
  }
  return tropVar;
}

tropicalVarietySortedByDimension()

ZConesSortedByDimension tropicalVarietySortedByDimension	(	const poly	g,
		const ring	r,
		const tropicalStrategy *	currentCase
	)

Definition at line 62 of file tropicalVarietyOfPolynomials.cc.

{
  int n = rVar(r);
  ZConesSortedByDimension tropVar;
  if (g && g->next)
  {
    int* expv = (int*) omAlloc((n+1)*sizeof(int));
    gfan::ZMatrix exponents = gfan::ZMatrix(0,n);
    for (poly s=g; s; pIter(s))
    {
      p_GetExpV(s,expv,r);
      gfan::ZVector zv = intStar2ZVector(n,expv);
      exponents.appendRow(intStar2ZVector(n,expv));
    }
    omFreeSize(expv,(n+1)*sizeof(int));
 
    int l = exponents.getHeight();
    gfan::ZVector lowerHalfSpaceCondition = gfan::ZVector(n);
    lowerHalfSpaceCondition[0] = -1;
    for (int i=0; i<l; i++)
    {
      for (int j=i+1; j<l; j++)
      {
        gfan::ZMatrix equation = gfan::ZMatrix(0,n);
        equation.appendRow(exponents[i].toVector()-exponents[j].toVector());
        gfan::ZMatrix inequalities = gfan::ZMatrix(0,n);
        if (currentCase->restrictToLowerHalfSpace())
          inequalities.appendRow(lowerHalfSpaceCondition);
        for (int k=0; k<l; k++)
          if (k!=i && k!=j) inequalities.appendRow(exponents[i].toVector()-exponents[k].toVector());
        gfan::ZCone zc = gfan::ZCone(inequalities,equation);
        if (zc.dimension()>=n-1)
        {
          zc.canonicalize();
          tropVar.insert(zc);
        }
      }
    }
  }
  return tropVar;
}