source: git/factory/facFactorize.h @ ab547e2

/*****************************************************************************\
 * Computer Algebra System SINGULAR
\*****************************************************************************/
/** @file facFactorize.h
 *
 * multivariate factorization over Q(a)
 *
 * @author Martin Lee
 *
 * @internal @version \$Id$
 *
 **/
/*****************************************************************************/

#ifndef FAC_FACTORIZE_H
#define FAC_FACTORIZE_H

#include <config.h>

#include "facBivar.h"
#include "facFqBivarUtil.h"

/// Factorization over Q (a)
///
/// @return @a multiFactorize returns a factorization of F
CFList
multiFactorize (const CanonicalForm& F,     ///< [in] poly to be factored
                const Variable& v           ///< [in] some algebraic variable
               );

/// factorize a squarefree multivariate polynomial over \f$ Q(\alpha) \f$
///
/// @return @a ratSqrfFactorize returns a list of monic factors, the first
///         element is the leading coefficient.
inline
CFList ratSqrfFactorize (const CanonicalForm & F, ///< [in] a multivariate poly
                         const Variable& v
                       )
{
  if (getNumVars (F) == 2)
    return ratBiSqrfFactorize (F, v);
  CFList result= multiFactorize (F, v);
  if (isOn (SW_RATIONAL))
  {
    normalize (result);
    result.insert (Lc(F));
  }
  return result;
}

/// factorize a multivariate polynomial over \f$ Q(\alpha) \f$
///
/// @return @a ratFactorize returns a list of monic factors with
///         multiplicity, the first element is the leading coefficient.
inline
CFFList ratFactorize (const CanonicalForm& F, ///< [in] a multivariate poly
                      const Variable& v
                    )
{
  if (getNumVars (F) == 2)
  {
    CFFList result= ratBiFactorize (F,v);
    return result;
  }
  Variable a= Variable (1);
  CanonicalForm LcF= Lc (F);

  CanonicalForm sqrfP= sqrfPart (F);
  CFList buf;
  CFFList result;
  buf= multiFactorize (sqrfP, v);
  CanonicalForm G= F;
  result= multiplicity (G, buf);
  if (isOn (SW_RATIONAL))
  {
    normalize (result);
    result.insert (CFFactor (LcF, 1));
  }
  return result;
}

#endif