loops_upoldse.hpp

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/********************************************************************
 *   This file is part of the source code of the realroot library.
 *   Author(s): J.P. Pavone, GALAAD, INRIA
 *   $Id: upoldse.hpp,v 1.1 2005/07/11 10:03:56 jppavone Exp $
 ********************************************************************/
#ifndef realroot_SOLVE_SBDSLV_LOOPS_UPOLDSE_HPP
#define realroot_SOLVE_SBDSLV_LOOPS_UPOLDSE_HPP
//--------------------------------------------------------------------
namespace mmx {
//--------------------------------------------------------------------
namespace upoldse_ /* univariate dense polynomial loops */
{
template<typename real_t> inline /* differentiation */
void diff( real_t * dst, real_t const * const src, unsigned sz, int st )
{
    for ( unsigned i = 0; i < sz-1; dst[i*st] = (i+1)*src[(i+1)*st],  i ++ ) ;
}
template<typename coeff_t,typename parm_t> inline /* évaluation */
void horner( parm_t& res, coeff_t const * const mnms, unsigned sz, const parm_t& t, int st = 1  )
{
    res = 0.0;
    for ( int p = (sz-1)*st; p != 0; res +=  mnms[p], res *= t, p -= st ) ;
    res+=mnms[0];
}
template<typename real_t> inline  /* évaluation */
real_t horner( real_t const * const mnms, unsigned sz, const real_t& t, int st = 1  )
{
    real_t res;
    horner(res,mnms,sz,t,st);
    return res;
}
template<typename real_t> inline  /* A FAIRE: utiliser st ! */
void dhorner( real_t& p, real_t& dp, real_t const * const mnms, unsigned sz, const real_t& t )/*, int st = 1 )*/
{
    int n = sz-1;
    p = mnms[n], dp  = 0.0;
    for ( int j = n-1; j>=0; dp=dp*t+p, p=p*t+mnms[j], j-- ) ;
}

//     template<typename real_t> inline  /* x <- x+c */
//     void shift( real_t * d, unsigned sz, int st, const real_t& c  )
//     { 
//       int j,k; 
//       for ( j = 0; j <= sz-2; j++ )
//  for( k =n-2; k >= j; d[k*st] += c*d[(k+1)*st], k--); 
//     };
};
//--------------------------------------------------------------------
} //namespace mmx
/********************************************************************/
#endif //