flintcf_Zn.cc File Reference

#include <ctype.h>
#include "misc/auxiliary.h"
#include <flint/flint.h>
#include <flint/nmod_poly.h>
#include "factory/factory.h"
#include "coeffs/coeffs.h"
#include "coeffs/numbers.h"
#include "coeffs/longrat.h"
#include "coeffs/modulop.h"
#include "coeffs/flintcf_Zn.h"

Go to the source code of this file.

Typedefs
typedef nmod_poly_struct *	nmod_poly_ptr

Functions
static const char *	Eati (const char *s, int *i)
static BOOLEAN	CoeffIsEqual (const coeffs r, n_coeffType n, void *parameter)
static void	KillChar (coeffs cf)
static void	SetChar (const coeffs r)
static number	Mult (number a, number b, const coeffs c)
static number	Sub (number a, number b, const coeffs c)
static number	Add (number a, number b, const coeffs c)
static number	Div (number a, number b, const coeffs c)
static number	ExactDiv (number a, number b, const coeffs c)
static number	IntMod (number a, number b, const coeffs c)
static number	Init (long i, const coeffs r)
static number	InitMPZ (mpz_t i, const coeffs r)
static int	Size (number n, const coeffs r)
static long	Int (number &n, const coeffs r)
static void	MPZ (mpz_t result, number &n, const coeffs r)
static number	Neg (number a, const coeffs r)
static number	Invers (number a, const coeffs r)
static number	Copy (number a, const coeffs r)
static BOOLEAN	IsOne (number a, const coeffs r)
static BOOLEAN	IsZero (number a, const coeffs r)
static void	WriteShort (number a, const coeffs r)
static const char *	Read (const char *st, number *a, const coeffs r)
static void	Normalize (number &a, const coeffs r)
static BOOLEAN	Greater (number a, number b, const coeffs r)
static BOOLEAN	Equal (number a, number b, const coeffs r)
static BOOLEAN	IsMOne (number k, const coeffs r)
static BOOLEAN	GreaterZero (number k, const coeffs r)
static void	Power (number a, int i, number *result, const coeffs r)
static number	Gcd (number a, number b, const coeffs r)
static number	ExtGcd (number a, number b, number *s, number *t, const coeffs r)
static number	Lcm (number a, number b, const coeffs r)
static void	Delete (number *a, const coeffs r)
static nMapFunc	SetMap (const coeffs src, const coeffs dst)
static number	Init_bigint (number i, const coeffs dummy, const coeffs dst)
static number	Farey (number p, number n, const coeffs)
static number	ChineseRemainder (number *x, number *q, int rl, BOOLEAN sym, CFArray &inv_cache, const coeffs)
static int	ParDeg (number x, const coeffs r)
static number	Parameter (const int i, const coeffs r)
static char *	CoeffName (const coeffs r)
coeffs	flintZnInitCfByName (char *s, n_coeffType n)
static void	WriteFd (number a, const ssiInfo *d, const coeffs)
static number	ReadFd (const ssiInfo *d, const coeffs r)
static BOOLEAN	DBTest (number a, const char *f, const int l, const coeffs r)
BOOLEAN	flintZn_InitChar (coeffs cf, void *infoStruct)

Typedef Documentation

nmod_poly_ptr

typedef nmod_poly_struct* nmod_poly_ptr

Definition at line 24 of file flintcf_Zn.cc.

Function Documentation

Add()

static number Add ( number  a, number  b, const coeffs  c  )

static

Definition at line 77 of file flintcf_Zn.cc.

{
  nmod_poly_ptr res=(nmod_poly_ptr)omAlloc(sizeof(nmod_poly_t));
  nmod_poly_init(res,c->ch);
  nmod_poly_add(res,(nmod_poly_ptr)a,(nmod_poly_ptr)b);
  return (number)res;
}

ChineseRemainder()

static number ChineseRemainder ( number *  x, number *  q, int  rl, BOOLEAN  sym, CFArray &  inv_cache, const  coeffs  )

static

Definition at line 394 of file flintcf_Zn.cc.

{
  WerrorS("not yet: ChineseRemainder");
  return NULL;
}

CoeffIsEqual()

static BOOLEAN CoeffIsEqual ( const coeffs  r, n_coeffType  n, void *  parameter  )

static

Definition at line 47 of file flintcf_Zn.cc.

{
  flintZn_struct *pp=(flintZn_struct*)parameter;
  return (r->type==n) &&(r->ch==pp->ch)
          &&(r->pParameterNames!=NULL)
          &&(strcmp(r->pParameterNames[0],pp->name)==0);
}

CoeffName()

static char * CoeffName ( const coeffs  r )

static

Definition at line 426 of file flintcf_Zn.cc.

{
  STATIC_VAR char CoeffName_flint_Zn[20];
  sprintf(CoeffName_flint_Zn,"flint:Z/%d[%s]",r->ch,r->pParameterNames[0]);
  return (char*)CoeffName_flint_Zn;
}

Copy()

static number Copy ( number  a, const coeffs  r  )

static

Definition at line 197 of file flintcf_Zn.cc.

{
 nmod_poly_ptr res=(nmod_poly_ptr)omAlloc(sizeof(nmod_poly_t));
 nmod_poly_init(res,r->ch);
 nmod_poly_set(res,(nmod_poly_ptr)a);
 return (number)res;
}

DBTest()

static BOOLEAN DBTest ( number  a, const char *  f, const int  l, const coeffs  r  )

static

Definition at line 481 of file flintcf_Zn.cc.

{
  return TRUE;
}

Delete()

static void Delete ( number *  a, const coeffs  r  )

static

Definition at line 349 of file flintcf_Zn.cc.

{
  if ((*a)!=NULL)
  {
    nmod_poly_clear((nmod_poly_ptr)*a);
    omFree(*a);
    *a=NULL;
  }
}

Div()

static number Div ( number  a, number  b, const coeffs  c  )

static

Definition at line 84 of file flintcf_Zn.cc.

{
  nmod_poly_ptr res=(nmod_poly_ptr)omAlloc(sizeof(nmod_poly_t));
  nmod_poly_init(res,c->ch);
  if(nmod_poly_is_zero((nmod_poly_ptr)b))
  {
     WerrorS(nDivBy0);
  }
  else
  {
    nmod_poly_div(res,(nmod_poly_ptr)a,(nmod_poly_ptr)b);
    nmod_poly_t mod;
    nmod_poly_init(mod,c->ch);
    nmod_poly_rem(mod,(nmod_poly_ptr)a,(nmod_poly_ptr)b);
    if (!nmod_poly_is_zero((nmod_poly_ptr)mod))
    {
      WerrorS("cannot divide");
    }
    nmod_poly_clear(mod);
  }
  return (number)res;
}

Eati()

static const char * Eati ( const char *  s, int *  i  )

static

Definition at line 29 of file flintcf_Zn.cc.

{
 
  if (((*s) >= '0') && ((*s) <= '9'))
  {
    unsigned long ii=0L;
    do
    {
      ii *= 10;
      ii += *s++ - '0';
    }
    while (((*s) >= '0') && ((*s) <= '9'));
    *i=(int)ii;
  }
  else (*i) = 1;
  return s;
}

Equal()

static BOOLEAN Equal ( number  a, number  b, const coeffs  r  )

static

Definition at line 297 of file flintcf_Zn.cc.

{
  return (nmod_poly_equal((nmod_poly_ptr)a,(nmod_poly_ptr)b));
}

ExactDiv()

static number ExactDiv ( number  a, number  b, const coeffs  c  )

static

Definition at line 106 of file flintcf_Zn.cc.

{
  nmod_poly_ptr res=(nmod_poly_ptr)omAlloc(sizeof(nmod_poly_t));
  nmod_poly_init(res,c->ch);
  if(nmod_poly_is_zero((nmod_poly_ptr)b))
  {
     WerrorS(nDivBy0);
  }
  else
    nmod_poly_div(res,(nmod_poly_ptr)a,(nmod_poly_ptr)b);
  return (number)res;
}

ExtGcd()

static number ExtGcd ( number  a, number  b, number *  s, number *  t, const coeffs  r  )

static

Definition at line 335 of file flintcf_Zn.cc.

{
  nmod_poly_ptr res=(nmod_poly_ptr)omAlloc(sizeof(nmod_poly_t));
  nmod_poly_init(res,r->ch);
  nmod_poly_init((nmod_poly_ptr)*s,r->ch);
  nmod_poly_init((nmod_poly_ptr)*t,r->ch);
  nmod_poly_xgcd(res,(nmod_poly_ptr)*s,(nmod_poly_ptr)*t,(nmod_poly_ptr)a,(nmod_poly_ptr)b);
  return (number)res;
}

Farey()

static number Farey ( number  p, number  n, const  coeffs  )

static

Definition at line 389 of file flintcf_Zn.cc.

{
  WerrorS("not yet: Farey");
  return NULL;
}

flintZn_InitChar()

BOOLEAN flintZn_InitChar	(	coeffs	cf,
		void *	infoStruct
	)

Definition at line 486 of file flintcf_Zn.cc.

{
  flintZn_struct *pp=(flintZn_struct*)infoStruct;
  cf->ch=pp->ch;
 
  cf->cfCoeffName    = CoeffName;
  cf->nCoeffIsEqual  = CoeffIsEqual;
  cf->cfKillChar     = KillChar;
  cf->cfSetChar      = SetChar;
  cf->cfMult         = Mult;
  cf->cfSub          = Sub;
  cf->cfAdd          = Add;
  cf->cfDiv          = Div;
  cf->cfExactDiv     = ExactDiv; // ???
  cf->cfInit         = Init;
  cf->cfInitMPZ      = InitMPZ;
  cf->cfSize         = Size;
  cf->cfInt          = Int;
  cf->cfMPZ          = MPZ;
  cf->cfInpNeg       = Neg;
  cf->cfInvers       = Invers;
  cf->cfCopy         = Copy;
  cf->cfRePart       = Copy;
  // default: cf->cfImPart       = ndReturn0;
  cf->cfWriteLong    = WriteShort; //WriteLong;
  cf->cfWriteShort = WriteShort;
  cf->cfRead         = Read;
  cf->cfNormalize    = Normalize;
 
  //cf->cfDivComp=
  //cf->cfIsUnit=
  //cf->cfGetUnit=
  //cf->cfDivBy=
 
  cf->cfGreater=Greater;
  cf->cfEqual  =Equal;
  cf->cfIsZero =IsZero;
  cf->cfIsOne  =IsOne;
  cf->cfIsMOne =IsMOne;
  cf->cfGreaterZero=GreaterZero;
 
  cf->cfPower        = Power;
  //default: cf->cfGetDenom     = GetDenom;
  //default: cf->cfGetNumerator = GetNumerator;
  cf->cfGcd          = Gcd;
  cf->cfExtGcd         = ExtGcd;
  cf->cfLcm          = Lcm;
  cf->cfDelete       = Delete;
  cf->cfSetMap       = SetMap;
  // default: cf->cfInpMult
  // default: cf->cfInpAdd
  cf->cfFarey        =Farey;
  cf->cfChineseRemainder=ChineseRemainder;
  cf->cfParDeg = ParDeg;
  cf->cfParameter = Parameter;
  //  cf->cfClearContent = ClearContent;
  //  cf->cfClearDenominators = ClearDenominators;
  //cf->convFactoryNSingN=ConvFactoryNSingN;
  //cf->convSingNFactoryN=ConvSingNFactoryN;
  cf->cfWriteFd = WriteFd;
  cf->cfReadFd  = ReadFd;
#ifdef LDEBUG
  cf->cfDBTest       = DBTest;
#endif
 
  cf->iNumberOfParameters = 1;
  char **pn=(char**)omAlloc0(sizeof(char*));
  pn[0]=(char*)omStrDup(pp->name);
  cf->pParameterNames = (const char **)pn;
  cf->has_simple_Inverse= FALSE;
  cf->has_simple_Alloc= FALSE;
  cf->is_field=FALSE;
 
  return FALSE;
}

flintZnInitCfByName()

coeffs flintZnInitCfByName	(	char *	s,
		n_coeffType	n
	)

Definition at line 432 of file flintcf_Zn.cc.

{
  const char start[]="flint:Z/";
  const int start_len=strlen(start);
  if (strncmp(s,start,start_len)==0)
  {
    s+=start_len;
    int p;
    char st[10];
    int l=sscanf(s,"%d[%s",&p,st);
    if (l==2)
    {
      flintZn_struct info;
      info.ch=p;
      while (st[strlen(st)-1]==']') st[strlen(st)-1]='\0';
      info.name=st;
      return nInitChar(n,(void*)&info);
    }
  }
  return NULL;
}

Gcd()

static number Gcd ( number  a, number  b, const coeffs  r  )

static

Definition at line 328 of file flintcf_Zn.cc.

{
  nmod_poly_ptr res=(nmod_poly_ptr)omAlloc(sizeof(nmod_poly_t));
  nmod_poly_init(res,r->ch);
  nmod_poly_gcd(res,(nmod_poly_ptr)a,(nmod_poly_ptr)b);
  return (number)res;
}

Greater()

static BOOLEAN Greater ( number  a, number  b, const coeffs  r  )

static

Definition at line 282 of file flintcf_Zn.cc.

{
  if (nmod_poly_length((nmod_poly_ptr)a)>nmod_poly_length((nmod_poly_ptr)b))
    return TRUE;
   else if (nmod_poly_length((nmod_poly_ptr)a)<nmod_poly_length((nmod_poly_ptr)b))
     return FALSE;
   for(int i=nmod_poly_length((nmod_poly_ptr)a);i>=0;i--)
   {
     slong ac=nmod_poly_get_coeff_ui((nmod_poly_ptr)a,i);
     slong bc=nmod_poly_get_coeff_ui((nmod_poly_ptr)b,i);
     if (ac>bc) return TRUE;
     else if (ac<bc) return FALSE;
   }
   return FALSE;
}

GreaterZero()

static BOOLEAN GreaterZero ( number  k, const coeffs  r  )

static

Definition at line 315 of file flintcf_Zn.cc.

{
  // does it have a leading sign?
  // no: 0 and 1 do not have, everything else is in (...)
  return TRUE;
}

Init()

static number Init ( long  i, const coeffs  r  )

static

Definition at line 125 of file flintcf_Zn.cc.

{
  nmod_poly_ptr res=(nmod_poly_ptr)omAlloc(sizeof(nmod_poly_t));
  nmod_poly_init(res,r->ch);
  i= i%r->ch;
  if (i<0) i+=r->ch;
  nmod_poly_set_coeff_ui(res,0,i);
  return (number)res;
}

Init_bigint()

static number Init_bigint ( number  i, const coeffs  dummy, const coeffs  dst  )

static

Definition at line 369 of file flintcf_Zn.cc.

{
  nmod_poly_ptr res=(nmod_poly_ptr)omAlloc(sizeof(nmod_poly_t));
  nmod_poly_init(res,dst->ch);
  long ii;
  if (SR_HDL(i) & SR_INT)
  {
    ii=SR_TO_INT(i) % dst->ch;
  }
  else
  {
    mpz_t tmp;
    mpz_init(tmp);
    ii=mpz_mod_ui(tmp,i->z,dst->ch);
    mpz_clear(tmp);
  }
  if (ii<0) ii+=dst->ch;
  nmod_poly_set_coeff_ui(res,0,ii);
  return (number)res;
}

InitMPZ()

static number InitMPZ ( mpz_t  i, const coeffs  r  )

static

Definition at line 134 of file flintcf_Zn.cc.

{
  nmod_poly_ptr res=(nmod_poly_ptr)omAlloc(sizeof(nmod_poly_t));
  nmod_poly_init(res,r->ch);
  mpz_t tmp;
  mpz_init(tmp);
  slong ii=mpz_mod_ui(tmp,i,r->ch);
  mpz_clear(tmp);
  nmod_poly_set_coeff_ui(res,0,ii);
  return (number)res;
}

Int()

static long Int ( number &  n, const coeffs  r  )

static

Definition at line 149 of file flintcf_Zn.cc.

{
  if (nmod_poly_degree((nmod_poly_ptr)n)==0)
  {
    slong m;
    m=nmod_poly_get_coeff_ui((nmod_poly_ptr)n,0);
    return (long)m;
  }
  return 0;
}

IntMod()

static number IntMod ( number  a, number  b, const coeffs  c  )

static

Definition at line 118 of file flintcf_Zn.cc.

{
  nmod_poly_ptr res=(nmod_poly_ptr)omAlloc(sizeof(nmod_poly_t));
  nmod_poly_init(res,c->ch);
  nmod_poly_rem(res,(nmod_poly_ptr)a,(nmod_poly_ptr)b);
  return (number)res;
}

Invers()

static number Invers ( number  a, const coeffs  r  )

static

Definition at line 174 of file flintcf_Zn.cc.

{
  if(nmod_poly_is_zero((nmod_poly_ptr)a))
  {
    WerrorS(nDivBy0);
    return NULL;
  }
  if (nmod_poly_degree((nmod_poly_ptr)a)==0)
  {
    nmod_poly_ptr res=(nmod_poly_ptr)omAlloc(sizeof(nmod_poly_t));
    nmod_poly_init(res,r->ch);
    slong c=nmod_poly_get_coeff_ui((nmod_poly_ptr)a,0);
    extern number  nvInvers (number c, const coeffs r);
    c=(slong)nvInvers((number)c,r);
    nmod_poly_set_coeff_ui((nmod_poly_ptr)a,0,c);
    return (number)res;
  }
  else
  {
    WerrorS("not invertable");
    return NULL;
  }
}

IsMOne()

static BOOLEAN IsMOne ( number  k, const coeffs  r  )

static

Definition at line 309 of file flintcf_Zn.cc.

{
  if (nmod_poly_length((nmod_poly_ptr)k)>0) return FALSE;
  slong m=nmod_poly_get_coeff_ui((nmod_poly_ptr)k,0);
  return (m+1==r->ch);
}

IsOne()

static BOOLEAN IsOne ( number  a, const coeffs  r  )

static

Definition at line 305 of file flintcf_Zn.cc.

{
  return nmod_poly_is_one((nmod_poly_ptr)a);
}

IsZero()

static BOOLEAN IsZero ( number  a, const coeffs  r  )

static

Definition at line 301 of file flintcf_Zn.cc.

{
  return nmod_poly_is_zero((nmod_poly_ptr)a);
}

KillChar()

static void KillChar ( coeffs  cf )

static

Definition at line 54 of file flintcf_Zn.cc.

{
  omFree((ADDRESS)(cf->pParameterNames[0]));
  omFreeSize(cf->pParameterNames,sizeof(char*));
}

Lcm()

static number Lcm ( number  a, number  b, const coeffs  r  )

static

Definition at line 344 of file flintcf_Zn.cc.

{
  WerrorS("not yet: Lcm");
  return NULL;
}

MPZ()

static void MPZ ( mpz_t  result, number &  n, const coeffs  r  )

static

Definition at line 159 of file flintcf_Zn.cc.

{
  mpz_init(result);
  if (nmod_poly_degree((nmod_poly_ptr)n)==0)
  {
    slong m;
    m=nmod_poly_get_coeff_ui((nmod_poly_ptr)n,0);
    mpz_set_ui(result,m);
  }
}

Mult()

static number Mult ( number  a, number  b, const coeffs  c  )

static

Definition at line 63 of file flintcf_Zn.cc.

{
  nmod_poly_ptr res=(nmod_poly_ptr)omAlloc(sizeof(*res));
  nmod_poly_init(res,c->ch);
  nmod_poly_mul(res,(nmod_poly_ptr)a,(nmod_poly_ptr)b);
  return (number)res;
}

Neg()

static number Neg ( number  a, const coeffs  r  )

static

Definition at line 169 of file flintcf_Zn.cc.

{
  nmod_poly_neg((nmod_poly_ptr)a,(nmod_poly_ptr)a);
  return a;
}

Normalize()

static void Normalize ( number &  a, const coeffs  r  )

static

Definition at line 279 of file flintcf_Zn.cc.

{
}

Parameter()

static number Parameter ( const int  i, const coeffs  r  )

static

Definition at line 403 of file flintcf_Zn.cc.

{
  nmod_poly_ptr res=(nmod_poly_ptr)omAlloc(sizeof(nmod_poly_t));
  nmod_poly_init(res,r->ch);
  nmod_poly_set_coeff_ui(res,1,1);
  return (number)res;
}

ParDeg()

static int ParDeg ( number  x, const coeffs  r  )

static

Definition at line 399 of file flintcf_Zn.cc.

{
  return nmod_poly_degree((nmod_poly_ptr)x);
}

Power()

static void Power ( number  a, int  i, number *  result, const coeffs  r  )

static

Definition at line 321 of file flintcf_Zn.cc.

{
  nmod_poly_ptr res=(nmod_poly_ptr)omAlloc(sizeof(nmod_poly_t));
  nmod_poly_init(res,r->ch);
  *result=(number)res;
  nmod_poly_pow((nmod_poly_ptr)(*result),(nmod_poly_ptr)a,i);
}

Read()

static const char * Read ( const char *  st, number *  a, const coeffs  r  )

static

Definition at line 245 of file flintcf_Zn.cc.

{
// we only read "monomials" (i.e. [-][digits][parameter]),
// everythings else (+,*,^,()) is left to the singular interpreter
  const char *s=st;
  *a=(number)omAlloc(sizeof(nmod_poly_t));
  nmod_poly_init((nmod_poly_ptr)(*a),r->ch);
  BOOLEAN neg=FALSE;
  if (*s=='-') { neg=TRUE; s++;}
  if (isdigit(*s))
  {
    int z;
    s=Eati((char *)s, &z);
    nmod_poly_set_coeff_ui((nmod_poly_ptr)(*a),0,z);
  }
  else if(strncmp(s,r->pParameterNames[0],strlen(r->pParameterNames[0]))==0)
  {
    nmod_poly_set_coeff_ui((nmod_poly_ptr)(*a),1,1);
    s+=strlen(r->pParameterNames[0]);
    if(isdigit(*s))
    {
      int i=1;
      s=Eati(s,&i);
      if (i!=1)
      {
        nmod_poly_set_coeff_ui((nmod_poly_ptr)(*a),1,0);
        nmod_poly_set_coeff_ui((nmod_poly_ptr)(*a),i,1);
      }
    }
  }
  if (neg)
    nmod_poly_neg((nmod_poly_ptr)(*a),(nmod_poly_ptr)(*a));
  return s;
}

ReadFd()

static number ReadFd ( const ssiInfo *  d, const coeffs  r  )

static

Definition at line 466 of file flintcf_Zn.cc.

{
  // format: len a_len .. a_0
  nmod_poly_ptr aa=(nmod_poly_ptr)omAlloc(sizeof(nmod_poly_t));
  nmod_poly_init(aa,r->ch);
  int l=s_readint(d->f_read);
  unsigned long ul;
  for (int i=l;i>=0;i--)
  {
    unsigned long ul=s_readlong(d->f_read);
    nmod_poly_set_coeff_ui(aa,i,ul);
  }
  return (number)aa;
}

SetChar()

static void SetChar ( const coeffs  r )

static

Definition at line 59 of file flintcf_Zn.cc.

{
  // dummy
}

SetMap()

static nMapFunc SetMap ( const coeffs  src, const coeffs  dst  )

static

Definition at line 358 of file flintcf_Zn.cc.

{
  WerrorS("not yet: SetMap");
  return NULL;
}

Size()

static int Size ( number  n, const coeffs  r  )

static

Definition at line 145 of file flintcf_Zn.cc.

{
  return nmod_poly_degree((nmod_poly_ptr)n);
}

Sub()

static number Sub ( number  a, number  b, const coeffs  c  )

static

Definition at line 70 of file flintcf_Zn.cc.

{
  nmod_poly_ptr res=(nmod_poly_ptr)omAlloc(sizeof(nmod_poly_t));
  nmod_poly_init(res,c->ch);
  nmod_poly_sub(res,(nmod_poly_ptr)a,(nmod_poly_ptr)b);
  return (number)res;
}

WriteFd()

static void WriteFd ( number  a, const ssiInfo *  d, const  coeffs  )

static

Definition at line 453 of file flintcf_Zn.cc.

{
  // format: len a_len .. a_0
  nmod_poly_ptr aa=(nmod_poly_ptr)a;
  int l=nmod_poly_length(aa);
  fprintf(d->f_write,"%d ",l);
  for(int i=l; i>=0; i--)
  {
    ulong ul=nmod_poly_get_coeff_ui(aa,i);
    fprintf(d->f_write,"%lu ", ul);
  }
}

WriteShort()

static void WriteShort ( number  a, const coeffs  r  )

static

Definition at line 215 of file flintcf_Zn.cc.

{
  //nmod_poly_print_pretty((nmod_poly_ptr)a,r->pParameterNames[0]);
  if (IsOne(a,r)) StringAppendS("1");
  else if (IsZero(a,r)) StringAppendS("0");
  else
  {
    StringAppendS("(");
    BOOLEAN need_plus=FALSE;
    for(int i=nmod_poly_length((nmod_poly_ptr)a);i>=0;i--)
    {
      slong m=nmod_poly_get_coeff_ui((nmod_poly_ptr)a,i);
      if (m!=0)
      {
        if (need_plus) StringAppendS("+");
        need_plus=TRUE;
        if (i>0)
        {
          if (m!=1) StringAppend("%d*",(int)m);
          if (i>1)
            StringAppend("%s^%d",r->pParameterNames[0],i);
          else if (i==1)
            StringAppend("%s",r->pParameterNames[0]);
        }
        else StringAppend("%d",(int)m);
      }
    }
    StringAppendS(")");
  }
}