flint_mpoly.cc

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// emacs edit mode for this file is -*- C++ -*-
/****************************************
*  Computer Algebra System SINGULAR     *
****************************************/
/*
* ABSTRACT: flint mpoly
*/
 
#include "misc/auxiliary.h"
#include "flintconv.h"
#include "flint_mpoly.h"
 
#ifdef HAVE_FLINT
#if __FLINT_RELEASE >= 20503
#include "coeffs/coeffs.h"
#include "coeffs/longrat.h"
#include "polys/monomials/p_polys.h"
 
#include <vector>
 
/****** ring conversion ******/
 
BOOLEAN convSingRFlintR(fmpq_mpoly_ctx_t ctx, const ring r)
{
  if (rRing_ord_pure_dp(r))
  {
    fmpq_mpoly_ctx_init(ctx,r->N,ORD_DEGREVLEX);
    return FALSE;
  }
  else if (rRing_ord_pure_Dp(r))
  {
    fmpq_mpoly_ctx_init(ctx,r->N,ORD_DEGLEX);
    return FALSE;
  }
  else if (rRing_ord_pure_lp(r))
  {
    fmpq_mpoly_ctx_init(ctx,r->N,ORD_LEX);
    return FALSE;
  }
  return TRUE;
}
 
BOOLEAN convSingRFlintR(nmod_mpoly_ctx_t ctx, const ring r)
{
  if (rRing_ord_pure_dp(r))
  {
    nmod_mpoly_ctx_init(ctx,r->N,ORD_DEGREVLEX,r->cf->ch);
    return FALSE;
  }
  else if (rRing_ord_pure_Dp(r))
  {
    nmod_mpoly_ctx_init(ctx,r->N,ORD_DEGLEX,r->cf->ch);
    return FALSE;
  }
  else if (rRing_ord_pure_lp(r))
  {
    nmod_mpoly_ctx_init(ctx,r->N,ORD_LEX,r->cf->ch);
    return FALSE;
  }
  return TRUE;
}
 
BOOLEAN convSingRFlintR(fmpz_mpoly_ctx_t ctx, const ring r)
{
  if (rRing_ord_pure_dp(r))
  {
    fmpz_mpoly_ctx_init(ctx,r->N,ORD_DEGREVLEX);
    return FALSE;
  }
  else if (rRing_ord_pure_Dp(r))
  {
    fmpz_mpoly_ctx_init(ctx,r->N,ORD_DEGLEX);
    return FALSE;
  }
  else if (rRing_ord_pure_lp(r))
  {
    fmpz_mpoly_ctx_init(ctx,r->N,ORD_LEX);
    return FALSE;
  }
  return TRUE;
}
 
/******** polynomial conversion ***********/
 
// memory allocation is not thread safe; singular polynomials must be constructed in serial
 
/*
    We agree the that result of a singular -> fmpq_mpoly conversion is
    readonly. This restricts the usage of the result in flint functions to
    const arguments. However, the real readonly conversion is currently only
    implemented in the threaded conversion below since it requires a scan of
    all coefficients anyways. The _fmpq_mpoly_clear_readonly_sing needs to
    be provided for a consistent interface in the polynomial operations.
*/
static void _fmpq_mpoly_clear_readonly_sing(fmpq_mpoly_t a, fmpq_mpoly_ctx_t ctx)
{
    fmpq_mpoly_clear(a, ctx);
}
 
void convSingPFlintMP(fmpq_mpoly_t res, fmpq_mpoly_ctx_t ctx, poly p, int lp, const ring r)
{
  fmpq_mpoly_init2(res, lp, ctx);
  ulong* exp=(ulong*)omAlloc((r->N+1)*sizeof(ulong));
  while(p!=NULL)
  {
    number n=pGetCoeff(p);
    fmpq_t c;
    convSingNFlintN_QQ(c,n);
    #if SIZEOF_LONG==8
    p_GetExpVL(p,(int64*)exp,r);
    fmpq_mpoly_push_term_fmpq_ui(res, c, exp, ctx);
    #else
    p_GetExpV(p,(int*)exp,r);
    fmpq_mpoly_push_term_fmpq_ui(res, c, &(exp[1]), ctx);
    #endif
    fmpq_clear(c);
    pIter(p);
  }
  fmpq_mpoly_reduce(res, ctx); // extra step for QQ ensures res has content canonically factored out
  omFreeSize(exp,(r->N+1)*sizeof(ulong));
}
 
poly convFlintMPSingP(fmpq_mpoly_t f, fmpq_mpoly_ctx_t ctx, const ring r)
{
  int d=fmpq_mpoly_length(f,ctx)-1;
  poly p=NULL;
  ulong* exp=(ulong*)omAlloc0((r->N+1)*sizeof(ulong));
  fmpq_t c;
  fmpq_init(c);
  for(int i=d; i>=0; i--)
  {
    fmpq_mpoly_get_term_coeff_fmpq(c,f,i,ctx);
    poly pp=p_Init(r);
    #if SIZEOF_LONG==8
    fmpq_mpoly_get_term_exp_ui(exp,f,i,ctx);
    p_SetExpVL(pp,(int64*)exp,r);
    #else
    fmpq_mpoly_get_term_exp_ui(&(exp[1]),f,i,ctx);
    p_SetExpV(pp,(int*)exp,r);
    #endif
    p_Setm(pp,r);
    number n=convFlintNSingN_QQ(c,r->cf);
    pSetCoeff0(pp,n);
    pNext(pp)=p;
    p=pp;
  }
  fmpq_clear(c);
  omFreeSize(exp,(r->N+1)*sizeof(ulong));
  p_Test(p,r);
  return p;
}
 
void convSingPFlintMP(fmpz_mpoly_t res, fmpz_mpoly_ctx_t ctx, poly p, int lp, const ring r)
{
  fmpz_mpoly_init2(res, lp, ctx);
  ulong* exp=(ulong*)omAlloc((r->N+1)*sizeof(ulong));
  while(p!=NULL)
  {
    number n=pGetCoeff(p);
    fmpz_t c;
    convSingNFlintN(c,n);
    #if SIZEOF_LONG==8
    p_GetExpVL(p,(int64*)exp,r);
    fmpz_mpoly_push_term_fmpz_ui(res, c, exp, ctx);
    #else
    p_GetExpV(p,(int*)exp,r);
    fmpz_mpoly_push_term_fmpz_ui(res, c, &(exp[1]), ctx);
    #endif
    fmpz_clear(c);
    pIter(p);
  }
  omFreeSize(exp,(r->N+1)*sizeof(ulong));
}
 
poly convFlintMPSingP(fmpz_mpoly_t f, fmpz_mpoly_ctx_t ctx, const ring r)
{
  int d=fmpz_mpoly_length(f,ctx)-1;
  poly p=NULL;
  ulong* exp=(ulong*)omAlloc0((r->N+1)*sizeof(ulong));
  fmpz_t c;
  fmpz_init(c);
  for(int i=d; i>=0; i--)
  {
    fmpz_mpoly_get_term_coeff_fmpz(c,f,i,ctx);
    poly pp=p_Init(r);
    #if SIZEOF_LONG==8
    fmpz_mpoly_get_term_exp_ui(exp,f,i,ctx);
    p_SetExpVL(pp,(int64*)exp,r);
    #else
    fmpz_mpoly_get_term_exp_ui(&(exp[1]),f,i,ctx);
    p_SetExpV(pp,(int*)exp,r);
    #endif
    p_Setm(pp,r);
    number n=convFlintNSingN(c,r->cf);
    pSetCoeff0(pp,n);
    pNext(pp)=p;
    p=pp;
  }
  fmpz_clear(c);
  omFreeSize(exp,(r->N+1)*sizeof(ulong));
  p_Test(p,r);
  return p;
}
 
poly convFlintMPSingP(nmod_mpoly_t f, nmod_mpoly_ctx_t ctx, const ring r)
{
  int d=nmod_mpoly_length(f,ctx)-1;
  poly p=NULL;
  ulong* exp=(ulong*)omAlloc0((r->N+1)*sizeof(ulong));
  for(int i=d; i>=0; i--)
  {
    ulong c=nmod_mpoly_get_term_coeff_ui(f,i,ctx);
    poly pp=p_Init(r);
    #if SIZEOF_LONG==8
    nmod_mpoly_get_term_exp_ui(exp,f,i,ctx);
    p_SetExpVL(pp,(int64*)exp,r);
    #else
    nmod_mpoly_get_term_exp_ui(&(exp[1]),f,i,ctx);
    p_SetExpV(pp,(int*)exp,r);
    #endif
    p_Setm(pp,r);
    pSetCoeff0(pp,(number)c);
    pNext(pp)=p;
    p=pp;
  }
  omFreeSize(exp,(r->N+1)*sizeof(ulong));
  p_Test(p,r);
  return p;
}
 
void convSingPFlintMP(nmod_mpoly_t res, nmod_mpoly_ctx_t ctx, poly p, int lp,const ring r)
{
  nmod_mpoly_init2(res, lp, ctx);
  ulong* exp=(ulong*)omAlloc((r->N+1)*sizeof(ulong));
  while(p!=NULL)
  {
    number n=pGetCoeff(p);
    #if SIZEOF_LONG==8
    p_GetExpVL(p,(int64*)exp,r);
    nmod_mpoly_push_term_ui_ui(res, (ulong)n, exp, ctx);
    #else
    p_GetExpV(p,(int*)exp,r);
    nmod_mpoly_push_term_ui_ui(res, (ulong)n, &(exp[1]), ctx);
    #endif
    pIter(p);
  }
  omFreeSize(exp,(r->N+1)*sizeof(ulong));
}
 
/****** polynomial operations ***********/
 
poly Flint_Mult_MP(poly p,int lp, poly q, int lq, fmpq_mpoly_ctx_t ctx, const ring r)
{
  fmpq_mpoly_t pp,qq,res;
  convSingPFlintMP(pp,ctx,p,lp,r); // pp read only
  convSingPFlintMP(qq,ctx,q,lq,r); // qq read only
  fmpq_mpoly_init(res,ctx);
  fmpq_mpoly_mul(res,pp,qq,ctx);
  poly pres=convFlintMPSingP(res,ctx,r);
  fmpq_mpoly_clear(res,ctx);
  _fmpq_mpoly_clear_readonly_sing(pp,ctx);
  _fmpq_mpoly_clear_readonly_sing(qq,ctx);
  fmpq_mpoly_ctx_clear(ctx);
  p_Test(pres,r);
  return pres;
}
 
poly Flint_Mult_MP(poly p,int lp, poly q, int lq, nmod_mpoly_ctx_t ctx, const ring r)
{
  nmod_mpoly_t pp,qq,res;
  convSingPFlintMP(pp,ctx,p,lp,r);
  convSingPFlintMP(qq,ctx,q,lq,r);
  nmod_mpoly_init(res,ctx);
  nmod_mpoly_mul(res,pp,qq,ctx);
  poly pres=convFlintMPSingP(res,ctx,r);
  nmod_mpoly_clear(res,ctx);
  nmod_mpoly_clear(pp,ctx);
  nmod_mpoly_clear(qq,ctx);
  nmod_mpoly_ctx_clear(ctx);
  p_Test(pres,r);
  return pres;
}
 
poly Flint_Mult_MP(poly p,int lp, poly q, int lq, fmpz_mpoly_ctx_t ctx, const ring r)
{
  fmpz_mpoly_t pp,qq,res;
  convSingPFlintMP(pp,ctx,p,lp,r); // pp read only
  convSingPFlintMP(qq,ctx,q,lq,r); // qq read only
  fmpz_mpoly_init(res,ctx);
  fmpz_mpoly_mul(res,pp,qq,ctx);
  poly pres=convFlintMPSingP(res,ctx,r);
  fmpz_mpoly_clear(res,ctx);
  fmpz_mpoly_clear(pp,ctx);
  fmpz_mpoly_clear(qq,ctx);
  fmpz_mpoly_ctx_clear(ctx);
  p_Test(pres,r);
  return pres;
}
 
// Zero will be returned if the division is not exact
poly Flint_Divide_MP(poly p,int lp, poly q, int lq, fmpq_mpoly_ctx_t ctx, const ring r)
{
  fmpq_mpoly_t pp,qq,res;
  convSingPFlintMP(pp,ctx,p,lp,r); // pp read only
  convSingPFlintMP(qq,ctx,q,lq,r); // qq read only
  fmpq_mpoly_init(res,ctx);
  fmpq_mpoly_divides(res,pp,qq,ctx);
  poly pres = convFlintMPSingP(res,ctx,r);
  fmpq_mpoly_clear(res,ctx);
  _fmpq_mpoly_clear_readonly_sing(pp,ctx);
  _fmpq_mpoly_clear_readonly_sing(qq,ctx);
  fmpq_mpoly_ctx_clear(ctx);
  p_Test(pres,r);
  return pres;
}
 
poly Flint_Divide_MP(poly p,int lp, poly q, int lq, nmod_mpoly_ctx_t ctx, const ring r)
{
  nmod_mpoly_t pp,qq,res;
  convSingPFlintMP(pp,ctx,p,lp,r);
  convSingPFlintMP(qq,ctx,q,lq,r);
  nmod_mpoly_init(res,ctx);
  nmod_mpoly_divides(res,pp,qq,ctx);
  poly pres=convFlintMPSingP(res,ctx,r);
  nmod_mpoly_clear(res,ctx);
  nmod_mpoly_clear(pp,ctx);
  nmod_mpoly_clear(qq,ctx);
  nmod_mpoly_ctx_clear(ctx);
  p_Test(pres,r);
  return pres;
}
 
poly Flint_GCD_MP(poly p,int lp,poly q,int lq,nmod_mpoly_ctx_t ctx,const ring r)
{
  nmod_mpoly_t pp,qq,res;
  convSingPFlintMP(pp,ctx,p,lp,r);
  convSingPFlintMP(qq,ctx,q,lq,r);
  nmod_mpoly_init(res,ctx);
  int ok=nmod_mpoly_gcd(res,pp,qq,ctx);
  poly pres;
  if (ok)
  {
    pres=convFlintMPSingP(res,ctx,r);
    p_Test(pres,r);
  }
  else
  {
    pres=p_One(r);
  }
  nmod_mpoly_clear(res,ctx);
  nmod_mpoly_clear(pp,ctx);
  nmod_mpoly_clear(qq,ctx);
  nmod_mpoly_ctx_clear(ctx);
  return pres;
}
 
poly Flint_GCD_MP(poly p,int lp,poly q,int lq,fmpq_mpoly_ctx_t ctx,const ring r)
{
  fmpq_mpoly_t pp,qq,res;
  convSingPFlintMP(pp,ctx,p,lp,r); // pp read only
  convSingPFlintMP(qq,ctx,q,lq,r); // qq read only
  fmpq_mpoly_init(res,ctx);
  int ok=fmpq_mpoly_gcd(res,pp,qq,ctx);
  poly pres;
  if (ok)
  {
    // Flint normalizes the gcd to be monic.
    // Singular wants a gcd defined over ZZ that is primitive and has a positive leading coeff.
    if (!fmpq_mpoly_is_zero(res, ctx))
    {
      fmpq_t content;
      fmpq_init(content);
      fmpq_mpoly_content(content, res, ctx);
      fmpq_mpoly_scalar_div_fmpq(res, res, content, ctx);
      fmpq_clear(content);
    }
    pres=convFlintMPSingP(res,ctx,r);
    p_Test(pres,r);
  }
  else
  {
    pres=p_One(r);
  }
  fmpq_mpoly_clear(res,ctx);
  _fmpq_mpoly_clear_readonly_sing(pp,ctx);
  _fmpq_mpoly_clear_readonly_sing(qq,ctx);
  fmpq_mpoly_ctx_clear(ctx);
  return pres;
}
 
poly Flint_GCD_MP(poly p,int lp,poly q,int lq,fmpz_mpoly_ctx_t ctx,const ring r)
{
  fmpz_mpoly_t pp,qq,res;
  convSingPFlintMP(pp,ctx,p,lp,r);
  convSingPFlintMP(qq,ctx,q,lq,r);
  fmpz_mpoly_init(res,ctx);
  int ok=fmpz_mpoly_gcd(res,pp,qq,ctx);
  poly pres;
  if (ok)
  {
    // Singular wants a gcd defined over ZZ that is primitive and has a positive leading coeff.
    pres=convFlintMPSingP(res,ctx,r);
    p_Test(pres,r);
  }
  else
  {
    pres=p_One(r);
  }
  fmpz_mpoly_clear(res,ctx);
  fmpz_mpoly_clear(pp,ctx);
  fmpz_mpoly_clear(qq,ctx);
  fmpz_mpoly_ctx_clear(ctx);
  return pres;
}
 
#endif
#endif