Function complexToStr

libpolys/coeffs/mpr_complex.cc:696–754

converts a gmp_complex to a string ( + I * )

// converts a gmp_complex to a string ( <real part> + I * <imaginary part> )
//
char *complexToStr( gmp_complex & c, const unsigned int oprec, const coeffs src )
{
  const char * complex_parameter = "I";
  int N = 1; // strlen(complex_parameter);

  if (nCoeff_is_long_C(src))
  {
    complex_parameter = n_ParameterNames(src)[0];
    N = strlen(complex_parameter);
  }

  assume( complex_parameter != NULL && N > 0);

  char *out,*in_imag,*in_real;

  c.SmallToZero();
  if ( !c.imag().isZero() )
  {

    in_real=floatToStr( c.real(), oprec );         // get real part
    in_imag=floatToStr( abs(c.imag()), oprec );    // get imaginary part

    if (nCoeff_is_long_C(src))
    {
      int len=(strlen(in_real)+strlen(in_imag)+7+N)*sizeof(char);
      out=(char*)omAlloc(len);
      memset(out,0,len);
      if (  !c.real().isZero() )  // (-23-i*5.43) or (15.1+i*5.3)
        sprintf(out,"(%s%s%s*%s)",in_real,c.imag().sign()>=0?"+":"-",complex_parameter,in_imag);
      else // (-i*43) or (i*34)
      {
        if (c.imag().isOne())
          sprintf(out,"%s", complex_parameter);
        else if (c.imag().isMOne())
          sprintf(out,"-%s", complex_parameter);
        else
          sprintf(out,"(%s%s*%s)",c.imag().sign()>=0?"":"-", complex_parameter,in_imag);
      }
    }
    else
    {
      int len=(strlen(in_real)+strlen(in_imag)+9) * sizeof(char);
      out=(char*)omAlloc( len );
      memset(out,0,len);
      if ( !c.real().isZero() )
        sprintf(out,"(%s%s%s)",in_real,c.imag().sign()>=0?"+I*":"-I*",in_imag);
      else
        sprintf(out,"(%s%s)",c.imag().sign()>=0?"I*":"-I*",in_imag);
    }
    omFree( (void *) in_real );
    omFree( (void *) in_imag );
  }
  else
  {
    out= floatToStr( c.real(), oprec );
  }

  return out;